Electro-optic reflective element assembly

ABSTRACT

A rearview mirror assembly for a vehicle includes an electro-optic reflective element with an overhang region at an edge region of a first substrate that extends beyond a corresponding edge region of a second substrate. A transparent electrical conductor is disposed at a second surface of the first substrate and a mirror reflector is disposed at a third surface of the second substrate. The mirror reflector includes a tab portion that at least partially encompasses an edge dimension of the second substrate. A non-conductive seal is disposed between the first and second substrates and encompasses at least a portion of the mirror reflector and at least a portion of a non-conductive perimeter region of the third surface. A first electrical connector connects to the transparent electrical conductor via the overhang region and a second electrical connector is in electrical connection with the tab portion of the mirror reflector.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/533,762, filed May 4, 2005 now U.S. Pat. No. 7,184,190,which is a 371 U.S. national phase application of PCT Application No.PCT/US2003/035381, filed Nov. 5, 2003, which claims priority of U.S.provisional applications, Ser. No. 60/490,111, filed Jul. 25, 2003 byMcCabe et al. for FLUSH ELECTROCHROMIC CELL; and Ser. No. 60/423,903,filed Nov. 5, 2002 by McCabe for ONE SIDED FLUSH ELECTROCHROMIC CELL;and U.S. patent application Ser. No. 10/533,762 is acontinuation-in-part of U.S. pat. application Ser. No. 10/528,269, filedMar. 17, 2005, which is a 371 application of PCT Application No.PCT/US2003/029776, filed Sep. 19, 2003, which claims priority of U.S.provisional applications, Ser. No. 60/412,275, filed Sep. 20, 2002 byMcCabe for ELECTROCHROMIC MIRROR ASSEMBLY; Ser. No. 60/424,116, filedNov. 5, 2002 by McCabe for ELECTROCHROMIC MIRROR ASSEMBLY; and Ser. No.60/489,816, filed Jul. 24, 2003 by McCabe for ELECTROCHROMIC MIRRORASSEMBLY, which are all hereby incorporated herein by reference in theirentireties.

FIELD OF THE INVENTION

The present invention relates to an electro-optic reflective elementassembly for an electro-optic mirror assembly, such as an electrochromicinterior or exterior rearview mirror assembly for a vehicle, and, moreparticularly, to an electro-optic rearview mirror assembly whichincludes an electro-optic reflective element assembly with a reducedbezel.

BACKGROUND OF THE INVENTION

Variable reflectivity mirror assemblies, such as electro-optic mirrorassemblies, such as electrochromic mirror assemblies, are known and arewidely implemented in vehicles. The reflective element assembly of sucha mirror assembly often includes two substrates or glass elements withan electrochromic medium sandwiched therebetween. The back or outersurface of the second substrate (commonly referred to as the fourthsurface of the reflective element assembly) may include a silveredcoating to provide reflectance of an image. Each substrate is coatedwith at least one conductive or semi-conductive layer, which conductelectricity to the electrochromic medium from an electrical connectorclipped or otherwise fastened or secured at least partially along anedge of the substrate and layer.

An example of a known electrochromic reflective element assembly isshown in FIGS. 1 and 2. The reflective element includes anelectrochromic (EC) medium layer 1 sandwiched between conductive layers2 and a seal 7 at a front glass substrate 3 and a rear glass substrate 4(and may include other conductive or semi-conductive layers). Thesubstrates are offset so that an upper edge of one substrate and itsconductive coating extends above the upper edge of the other substrate,while the lower edge of the other substrate and its conductive coatingextends below the lower edge of the other substrate. This offset allowsfor electrical connection of electrical connectors or busbars 5 to theconductive coatings of each substrate, as shown in FIG. 2. The busbarsor electrical connectors or clips extend substantially along the entireupper or lower edge of the respective substrate and coating. However, inorder to manufacture the mirror element to obtain the desired offset,one or more offset or stepped spacers or pins 6 (shown in phantom inFIG. 2) must be placed along one of the upper and lower edges of thesubstrates to properly space the substrates from one another and toprovide the offset along the edges when the substrates are placed in anassembly fixture.

As shown in FIG. 3, another conventional offset mirror element includesa coating on one of the substrates which provides a tab out portion 7for connection of an electrical clip thereto. The substrates are offsetin a similar manner as shown in the embodiment of FIGS. 1 and 2 toprovide clearance at the tab out portion for the electrical connection.Such an embodiment also requires a stepped spacer or pin to provide theappropriate spacing between the substrates and to set the offset betweenthe edges at the desired or appropriate amount.

Typically, it is desirable to minimize the size of the bezel or overlapof the casing/bezel (or even to eliminate the bezel) which extendsaround the reflective element of the mirror assembly. The bezel istypically required to extend over the front or first surface of theelectrochromic cell or reflective element assembly to cover or hide orconceal, for example, the seal around the electrochromic medium of theelectrochromic cell (that typically spaces the front substrate from therear substrate, such as described in U.S. Pat. No. 6,002,511, which ishereby incorporated herein by reference), in order to conceal or hidethe seal (and/or the electrical spring conductors, busbar conductors,clips, connectors and/or the like) which may otherwise be visible,particularly when the electrochromic medium is darkened. An exemplaryand effective means for hiding the seal and, thus, minimizing the sizeof the bezel is disclosed in U.S. Pat. No. 5,066,112, which is herebyincorporated herein by reference. Also, and such as described in U.S.Pat. No. 6,449,082, which is hereby incorporated herein by reference,there is typically an offset to allow the clip or connector to connectto the cell or substrate that may influence the size of the overlap orbezel.

In cells or reflective element assemblies that may provide a small bezelor no bezel, it is often difficult to make electrical contact to thesemi-conductive and/or conductive layers of the substrates with arestricted overhang between the substrates. A variety of methods havebeen used to provide electrical power to the semi-conductive and/orconductive layers of electrochromic cells, such as described in U.S.Pat. Nos. 5,066,112; 6,356,376; and 6,512,264, which are herebyincorporated herein by reference.

Therefore, there is a need in the art for an electrochromic mirrorelement which overcomes the above disadvantages and shortcomings of theprior art.

SUMMARY OF THE INVENTION

The present invention provides an electro-optic or electrochromicinterior or exterior rearview mirror assembly which includes anelectro-optic or electrochromic cell or reflective element assemblyhaving a pair of substrates and an electro-optic or electrochromicmedium disposed between the substrates. The reflective element assemblymay include electrical connectors for providing electrical current tothe conductive and/or semi-conductive layers or coatings at the surfacesof the substrates opposing the electro-optic medium. The electricalconnectors may connect to the substrates at or behind an overhang regionof the front substrate such that the connectors are substantially notviewable through the front substrate. The electrical connectors may beelectrically isolated from one another and may connect to one of thesubstrates and may provide electrical current to the respectivesubstrates. One edge or side of each of the substrates of the reflectiveelement assembly may be in flush alignment, while allowing forelectrical connection to one of the substrates along the generally flushedges.

According to an aspect of the present invention, a reflective elementassembly for a mirror system of a vehicle includes front and rearsubstrates with an electro-optic medium sandwiched therebetween, anon-conductive seal disposed around a perimeter of the electro-opticmedium and between the front and rear substrates, and first and secondelectrical connectors. The rear substrate has a smaller dimension acrossa dimension of the rear substrate than a corresponding dimension acrossthe front substrate such that the front substrate defines a firstoverhang region at a first edge of the front substrate that extendsbeyond a corresponding first edge of the rear substrate. The frontsubstrate has a first surface and a second surface opposite the firstsurface. The second surface faces the electro-optic medium, The frontsubstrate has at least one first conductive layer disposed on the secondsurface. The rear substrate has a third surface and a fourth surfaceopposite the third surface. The third surface faces the electro-opticmedium. The rear substrate has at least one second conductive layerdisposed on the third surface. The second conductive layer includes atab portion that extends at least to a second edge of the rearsubstrate. The rear substrate includes a non-conductive racewayproximate the second edge and devoid of the second conductive layerexcept at the tab portion. The non-conductive seal encompasses at leasta portion of the second conductive layer and at least a portion of theraceway. The first electrical connector is in electrical connection withthe first conductive layer and the second electrical connector is inelectrical connection with the tab portion of the second conductivelayer. The first electrical connector connects to the first conductivelayer at the first overhang region so as to be behind the frontsubstrate and substantially not viewable through the first surface ofthe front substrate.

The front substrate may include a hiding or concealing layer at theperimeter portions to substantially hide the connectors and seal fromview by the driver of the vehicle.

According to another aspect of the present invention, a reflectiveelement assembly for a mirror system for a vehicle includes front andrear substrates with an electro-optic medium sandwiched therebetween, anon-conductive seal disposed around a perimeter of the electro-opticmedium and between the front and rear substrates, and first and secondelectrical connectors. The rear substrate has a smaller dimension acrossa dimension of the rear substrate than a corresponding dimension acrossthe front substrate such that the front substrate defines a firstoverhang region at a first edge of the front substrate that extendsbeyond a corresponding first edge of the rear substrate. The frontsubstrate has a first surface and a second surface opposite the firstsurface. The second surface faces the electro-optic medium. The frontsubstrate has at least one first conductive layer disposed on the secondsurface. The rear substrate has a third surface and a fourth surfaceopposite the third surface. The third surface faces the electro-opticmedium. The third surface of the rear substrate has a non-conductiveportion proximate the first edge and devoid of the second conductivelayer. The non-conductive seal encompasses at least a portion of thenon-conductive portion of the rear substrate. The first electricalconnector is in electrical connection with the first conductive layerand the second electrical connector is in electrical connection with thesecond conductive layer. The first electrical connector extends from thefourth surface of the second substrate and over at least a portion ofthe first edge of the second substrate and toward the first overhangregion of the front substrate. The first electrical connector connectsto the first conductive surface at the first overhang region so as to bebehind the front substrate and substantially not viewable through thefirst surface of the front substrate. The non-conductive seal and thenon-conductive portion substantially electrically isolate the firstelectrical connector from the second conductive layer.

According to another aspect of the present invention, an electro-opticor electrochromic mirror element includes a pair of substrates and anelectro-optic or electrochromic medium sandwiched therebetween. Each ofthe pair of substrates includes at least one conductive orsemi-conductive layer disposed thereon. The pair of substrates arepositioned relative to one another such that the upper and/or loweredges of the substrates are substantially flush or aligned with oneanother. One of the substrates includes a relief area along the alignededge to provide clearance for electrical connection to the conductivelayer or layers of the other substrate along the aligned edge.

According to another aspect of the present invention, an electro-opticor electrochromic mirror assembly for a vehicle comprises anelectro-optic or electrochromic reflective element assembly comprising afirst substrate having first and second surfaces and a second substratehaving third and fourth surfaces. The first and second substrates arearranged so that the second surface opposes the third surface with anelectro-optic or electrochromic medium disposed therebetween. The firstsubstrate has at least one at least partially conductive coating orlayer on the second surface and the second substrate has at least one atleast partially conductive coating or layer on the third surface. Thefirst and second substrates are positioned relative to one another suchthat at least a portion of a first edge of the first substrate isgenerally flush or aligned with a corresponding edge of the secondsubstrate. The first edge of the first substrate has a relief areaformed therealong, wherein the relief area provides clearance forelectrical connection to the corresponding edge of the second substrate.

In one form, the conductive coating of the second substrate includes atab out portion at the corresponding edge. The relief area of the firstsubstrate provides clearance for electrical connection to the tab outportion of the at least one conductive coating or layer. The firstsubstrate may be the front substrate and the second substrate may be therear substrate, with the aligned or generally flush edges being alongthe upper edges of the substrates.

Therefore, the present invention provides an electro-optic orelectrochromic cell or mirror reflective element assembly that providesan overhang region at least one edge of the front substrate forelectrical connection to the conductive layer at the rear surface of thesubstrate, such that the electrical connection is not viewable throughthe front surface of the front substrate. The present invention thus mayprovide a reflective element assembly that is suitable for use in abezelless mirror assembly, where the front surface of the reflectiveelement is substantially entirely viewable by a driver of the vehicle.Optionally, a reflective element assembly of the present invention mayprovide a flush alignment of an upper and/or lower edge of a pair ofsubstrates, while providing clearance for electrical connection to theupper and/or lower edges of one of the substrates and the respectiveconductive coating. The present invention thus provides enhancedassembly processes for the mirror element, since the substrates may bealigned with one another within an assembly fixture and do not requirestepped pins or spacers positioned along one edge to provide sufficientoffset or staggering between the substrates to provide clearance forelectrical connection to one of the substrates along the aligned orflush edge thereof.

These and other objects, advantages, purposes, and features of thepresent invention will become apparent from the study of the followingdescription in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a conventional electrochromic mirror element,showing a typical offset orientation of the two substrates;

FIG. 2 is a sectional view of a conventional electrochromic mirrorelement, showing a conventional spacer for use in manufacturing of theconventional mirror element;

FIG. 3 is a plan view of another conventional electrochromic mirrorelement similar to FIG. 1, with a tab out portion for electricalconnection with a conductive or semi-conductive layer on one of thesubstrates;

FIG. 4 is a plan view of an electro-optic reflective element assembly ofthe present invention;

FIG. 5 is a sectional view of the reflective element assembly takenalong the line V-V in FIG. 4, showing the clearance provided forelectrical connection to each substrate;

FIG. 6 is a sectional view of the reflective element assembly takenalong the line VI-VI in FIG. 4, showing the flush alignment of the upperedge of the substrates;

FIG. 7 is a sectional view of a generally flush electro-optic reflectiveelement assembly in accordance with the present invention, withelectrically conducting pins providing the electrical connection to theappropriate semi-conductive layer of the substrates of the reflectiveelement assembly;

FIG. 8 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 9 is a sectional view of another flush electro-optic reflectiveelement assembly in accordance with the present invention, with anextruded wraparound connector for providing electrical contact to thesemi-conductive layers of the substrates of the reflective elementassembly;

FIG. 10 is a sectional view of another electro-optic reflective elementassembly similar to the reflective element assembly of FIG. 9;

FIG. 11 is a plan view of a generally flush electro-optic reflectiveelement assembly for an exterior rearview mirror assembly in accordancewith the present invention, with the substrates cut in generallyopposite wave patterns to facilitate electrical connection to therespective semi-conductive layers of the substrates;

FIG. 12 is an enlarged plan view of a portion of the reflective elementassembly of FIG. 11, with an electrical connector connecting to theexposed portion or wave peaks of an edge of one of the substrates of thereflective element assembly;

FIG. 13 is a plan view of another one sided flush electro-opticreflective element assembly in accordance with the present invention;

FIG. 14 is a plan view of the rear substrate of the reflective elementassembly of FIG. 13, with a semi-conductive layer or coating on thethird surface of the rear substrate;

FIG. 15 is a plan view of the rear substrate of FIG. 14, with a sealapplied or disposed around the perimeter surface or region of the rearsubstrate;

FIG. 16 is a perspective view of a front substrate and a rear substrateof an electro-optic reflective element assembly in accordance with thepresent invention;

FIG. 17 is a sectional view of an electro-optic reflective elementassembly having the substrates of FIG. 16;

FIG. 18 is an enlarged sectional view of an edge portion of the rearsubstrate of the electro-optic reflective element assembly of FIG. 17,showing an electrical connector extending from the rear surface of therear substrate;

FIGS. 19 and 19A are enlarged sectional views of an edge portion of theelectro-optic reflective element assembly of FIG. 17, showing anelectrical connector for providing electrical connection to the rearsurface of the front substrate;

FIG. 20 is another enlarged sectional view of a front substrate having aborder perimeter coating in accordance with the present invention;

FIG. 21 is a plan view of the rear surface of another electro-opticreflective element assembly in accordance with the present invention,with the electrical connections provided at the front substrate;

FIG. 22 is a plan view of the rear surface of another electro-opticreflective element assembly similar to FIG. 21, but with the electricalconnections provided at opposite corners of the reflective elementassembly;

FIG. 23 is an enlarged plan view of one of the corners of the reflectiveelement assembly of FIG. 22;

FIG. 24 is a plan view of another electro-optic reflective elementassembly similar to the reflective element assembly of FIG. 21;

FIG. 25A is a plan view of the third surface of a rear substrate for anexterior electro-optic reflective element assembly in accordance withthe present invention; and

FIG. 25B is a plan view of the second surface of a front substrate forthe exterior electro-optic reflective element assembly;

FIG. 26 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention, with the electricalconnections provided at the front substrate;

FIG. 27 is a plan view of the electro-optic reflective element assemblyof FIG. 26;

FIG. 28 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 29 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 30 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 31 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 32 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 33A is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIGS. 33B and 33C are plan views of the reflective element assembly ofFIG. 33A;

FIG. 34 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 35 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 36 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 37 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention;

FIG. 38 is a sectional view of another electro-optic reflective elementassembly in accordance with the present invention; and

FIG. 39 is a plan view of another electro-optic reflective elementassembly in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depictedtherein, an electro-optic or electrochromic cell or mirror elementassembly or reflective element assembly 10 for an interior rearviewmirror assembly of a vehicle (not shown) includes first and second glasssubstrates 12, 14 and an electro-optic or electrochromic medium 16disposed or sandwiched therebetween (FIGS. 4-6). Electrochromic medium16 and at least one metallic and/or non-metallic conductive orsemi-conductive layers 18, 20 are disposed on the inner surfaces 12 a,14 a of substrates 12, 14 and between the electrochromic medium 16 andthe respective substrate 12, 14. At least one of the edges or sides 12b, 14 b of the substrates 12, 14 are generally aligned with or flushwith one another (as seen in FIGS. 4 and 6) at least along a portion ofthe edges. The reflective element or mirror element of the presentinvention is equally suitable for interior or exterior rearview mirrorassemblies for vehicles or for other mirror assemblies, withoutaffecting the scope of the present invention.

Rear or second substrate 14 includes at least one layer or coating ofmetallic conductive (such as a layer of silver, aluminum or an alloy ofsilver or an alloy of aluminum or other metal or metal alloy) ornon-metallic semi-conductive material (such as an ITO layer or the like)20 disposed on a forward or third surface 14 a of rear substrate 14(shown in FIGS. 5 and 6 as three layers). The layers or coatings may beselected to provide sufficient reflectance of the mirror element and mayprovide a desired transmissivity if the mirror element includes adisplay at the fourth surface of the rear substrate, as discussed below.Optionally, the layers or coatings may define reflective and conductivelayers or stacks of the types described in PCT application No.PCT/JUS03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. forMIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 asInternational Publication No. WO 2004/026633 A2, which is herebyincorporated herein by reference. Such a stack of layers comprises ametallic layer sandwiched between two semi-conductive layers (both ofwhich preferably are the same material, but either of which can bedifferent from the other). As shown in FIGS. 4 and 5, at least one layer20 a is deposited directly on surface 14 a of substrate 14 and includesa tab out portion 21 extending toward and substantially up to edge 14 bat a generally central region 14 d thereof. An electrical clip 24 isconnected to tab out portion 21 to provide electricity to the layer orlayers 20 on substrate 14. The outer perimeter portion of rear substrate14 is masked during the coating process such that the coatings or layers20 do not cover surface 14 a at the outer perimeter portions except attab out portion 21.

The first substrate 12 of reflective element assembly 10 includes one ormore electrically conductive or semi-conductive layers 18 (shown inFIGS. 5 and 6 and a single layer), such as a tin oxide or indium tinoxide (ITO) or any other transparent electrically semi-conductive layeror coating or the like (such as indium cerium oxide (ICO), indiumtungsten oxide (IWO), indium oxide (IO) layers or the like, or a zincoxide layer or coating, or a zinc oxide coating or the like doped withaluminum or other metallic materials, such as silver or gold or thelike, or other oxides doped with a suitable metallic material or thelike), deposited on an inward surface 12 a of first substrate 12 (i.e.,the second surface 12 a of the mirror element assembly 10). As shown inFIGS. 5 and 6, coating 18 may extend substantially up to and along alower edge 12 c of substrate 12 and may be electrically connected to aclip or busbar 22 extending along edge 12 c to provide electricity tocoating or layer 18.

Rear or second substrate 14 includes at least one layer or coating ofmetallic conductive (such as a layer of silver, aluminum or an alloy ofsilver or an alloy of aluminum or other metal or metal alloy) ornon-metallic semi-conductive material (such as an ITO layer or the like)20 disposed on a forward or third surface 14 a of rear substrate 14(shown in FIGS. 5 and 6 as three layers). The layers or coatings may beselected to provide sufficient reflectance of the mirror element and mayprovide a desired transmissivity if the mirror element includes adisplay at the fourth surface of the rear substrate, as discussed below.Optionally, the layers or coatings may define reflective and conductivelayers or stacks of the types described in PCT application No.PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al. forMIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 asInternational Publication No. WO 2004/026633 A2, which is herebyincorporated herein by reference. Such a stack of layers comprises ametallic layer sandwiched between two semi-conductive layers (both ofwhich preferably are the same material, but either of which can bedifferent from the other). As shown in FIGS. 4 and 5, at least one layer20 a is deposited directly on surface 14 a of substrate 14 and includesa tab out portion 21 extending toward and substantially up to edge 14 bat a generally central region 14 d thereof. An electrical clip 24 isconnected to tab out portion 21 to provide electricity to the layer orlayers 20 on substrate 14. The outer perimeter portion of rear substrate14 is masked during the coating process such that the coatings or layers20 do not cover surface 14 a at the outer perimeter portions except attab out portion 21.

As can be seen in FIGS. 5 and 6, the first and second substrates 12, 14are positioned in spaced-apart relationship with one another with anelectro-optic or electrochromic medium 16 disposed betweensemi-conductive layer or layers 18 and semi-conductive layer or layers20. A non-conductive seal 19 is positioned around the perimeter of theelectrochromic medium 16 and around the perimeter of the semi-conductivelayer 20 except at the tab out portion 21. The electrochromic medium 16changes color or darkens in response to electricity or voltage appliedto or through the semi-conductive layers 18 and 20 at either side of theelectrochromic medium. The electrochromic medium 16 disposed between thefront and rear substrates 12, 14 may be a solid polymer matrixelectrochromic medium, such as is disclosed in U.S. Pat. No. 6,154,306,which is hereby incorporated by reference herein, or other suitablemedium, such as a liquid or solid medium or thin film or the like, suchas the types disclosed in U.S. pat. application, Ser. No. 09/793,002,filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMSINCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, and/orin U.S. Pat. Nos. 5,668,663 and 5,724,187, the entire disclosures ofwhich are hereby incorporated by reference herein, without affecting thescope of the present invention. The electrochromic mirror elementassembly may utilize the principles disclosed in commonly assigned U.S.Pat. Nos. 5,140,455; 5,151,816; 6,178,034; 6,154,306; 6,002,544;5,567,360; 5,525,264; 5,610,756; 5,406,414; 5,253,109; 5,076,673;5,073,012; 5,117,346; 5,724,187; 5,668,663; 5,910,854; 5,142,407 or4,712,879, which are hereby incorporated herein by reference, or asdisclosed in the following publications: N. R. Lynam, “ElectrochromicAutomotive Day/Night Mirrors”, SAE Technical Paper Series 870636 (1987);N. R. Lynam, “Smart Windows for Automobiles”, SAE Technical Paper Series900419 (1990); N. R. Lynam and A. Agrawal, “Automotive Applications ofChromogenic Materials”, Large Area Chromogenics: Materials and Devicesfor Transmittance Control, C. M. Lampert and C. G. Granquist, EDS.,Optical Engineering Press, Wash. (1990), which are hereby incorporatedby reference herein, and in U.S. pat. application Ser. No. 09/792,002,filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRROR SYSTEMSINCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268, which ishereby incorporated herein by reference. Mirror element assembly 10 mayalso include a seal (not shown) positioned around the outer portions ofthe layers 18, 20 and the electrochromic medium 16 to seal the layersand avoid corrosion of the metallic layer or layers.

During operation, a voltage may be applied to mirror element assembly 10via busbars or clips or electrical connectors 22, 24 positioned aroundand engaging at least a portion of an outer edge of the semi-conductivelayers 18, 20 (FIG. 5). The connectors may be connected to anappropriate power source or circuitry or control or the like, such as toa circuit board or the like at the rear of the electrochromic cell orreflective element assembly. Optionally, the circuitry may be applied tothe rear surface of the rear substrate utilizing the principlesdescribed in U.S. provisional application Ser. No. 60/508,086, filedOct. 2, 2003 by Schofield for MIRROR REFLECTIVE ELEMENT ASSEMBLYINCLUDING ELECTRONIC COMPONENT, which is hereby incorporated herein byreference.

The voltage applied by connectors 22, 24 is bled from semi-conductivelayers 18, 20 to the electrochromic medium 16. Preferably, the layersprovide for reduced resistance through the layers, which provides forfaster, more uniform coloration of the electrochromic medium 16, sincethe electrons applied via busbars 24 at semi-conductive layer 20 a maybleed through the other semi-conductive layers 20 faster due to theenhanced conductivity in the conductive layers 20. Preferably, thelayers 20 provide a sheet resistance of less than approximately 10 ohmsper square, more preferably less than approximately 5 ohms per square,and most preferably less than approximately 2 ohms per square.Desirably, and particularly for larger area mirrors, the sheetresistance is less than approximately 1 ohm per square, such as in therange of approximately 0.1 to 0.7 ohms per square.

In order to provide enhanced performance of the electrochromic mirrorelement, each of the layers of the combination or stack of layers mayhave substantial conductivity and none of the layers significantlyretard electron/electrical conductivity from one layer to the otherthroughout the stack, and, thus, do not impede the flow of electronsinto the electrochromic (EC) medium. In this regard, it is desirablethat one or more of the metallic layers comprises a metallic material(which is preferably a highly reflective material, such as silver orsilver alloys or the like) having a specific resistivity of preferablyless than approximately 5×10-5 ohm.cm, more preferably less thanapproximately 1×10-5 ohm.cm, and most preferably less than approximately5×10-6 ohm.cm. Preferably, such a highly conductive metallic layer orlayers is/are sandwiched between two non-metallic, partially conductivelayers, preferably formed of a non-metallic material (such as asemi-conducting oxide, such as indium oxide, tungsten oxide, tin oxide,doped tin oxide or the like) having a specific resistivity of less thanapproximately 1×10-2 ohm.cm, more preferably less than approximately1×10-3 ohm.cm, and most preferably less than approximately 5×10-4ohm.cm, such as disclosed in PCT application No. PCT/US03/29776, filedSep. 19, 2003 by Donnelly Corporation et al. for MIRROR REFLECTIVEELEMENT ASSEMBLY, published Apr. 1, 2004 as International PublicationNo. WO 2004/026633 A2, which is hereby incorporated herein by reference.

In the illustrated embodiment of FIGS. 4-6, semi-conductive layers 18,20 a are deposited on the inward surfaces 12 a, 14 a of the respectivesubstrates 12, 14. The semi-conductive layer 18, 20 a may be depositedon the glass or substrate 12, 14 via any suitable process. Theparticular thickness of the conductive layers may vary depending on theparticular application of mirror element 10. Optionally, thesemi-conductive layer 20 a on rear substrate 14 need not be transparentand may comprise a chromium layer or the like. However, thesemi-conductive layer 20 a may comprise a generally transparentsemi-conductive layer of coating, such as a tin oxide layer, an indiumtin oxide (ITO) layer or the like, without affecting the scope of thepresent invention.

The transparent semi-conductive non-metallic layers on rear substrate 14preferably comprise non-metallic transparent electrically conductive orsemi-conductive materials, such as tin oxide, indium oxide, indiumcerium oxide, indium tungsten oxide, nickel oxide, tungsten oxide,indium tin oxide, half-wave indium tin oxide, full wave indium tinoxide, doped tin oxides, such as antimony-doped tin oxide andfluorine-doped tin oxide, doped zinc oxides, such as antimony-doped zincoxide and aluminum-doped zinc oxide and/or the like.

The metallic layer or layers on rear substrate 14 comprise a thin filmor layer of metal, such as silver, aluminum, or alloys thereof, or thelike, with a selected thickness to provide sufficient reflectivityand/or transmissivity, depending on the application of the mirrorelement and whether the mirror element includes a display, such as adisplay-on-demand or display-on-need type of display or the like, asdiscussed below. Preferably, the selected metallic material comprisessilver, but may otherwise comprise a material selected from aluminum,silver alloys, aluminum alloys (such as 6061 or 1100 aluminum alloys orthe like), manganese, chromium or rhodium, or any other metallicmaterial which is sufficiently reflective and/or transmissive at aselected thickness, without affecting the scope of the presentinvention.

In a preferred embodiment, the semi-conductive layers 18, 20 a compriseindium tin oxide (ITO) and are deposited onto the surfaces 12 a, 14 a ofthe respective substrate 12, 14 via a hot deposition process, which mayinvolve, for example, sputter deposition onto a heated substrate, withthe heated substrate often being heated to a temperature of greater thanabout 200° C., sometimes greater than 300° C., as is known in the art.The combination of the semi-conductive layers 18, 20 a on the substrates12, 14 defines a conductive substrate which may be used for variousembodiments of a mirror element in accordance with the presentinvention.

The other semi-conductive layers and metallic layers of the layers 20 onrear substrate 14 (or other layers on front substrate 12) may bedeposited onto semi-conductive layer 20 a via a cold deposition process,such as sputter coating or the like, onto an unheated substrate.Preferably, each of the layers 20 is deposited on second substrate 14 bya sputter deposition process. More particularly, the substrate 14(including the semi-conductive layer 20 a already deposited thereon) maybe positioned in one or more sputter deposition chambers with eitherplanar or rotary magnetron targets, and with deposition of the layersbeing achieved by either reactive deposition of an oxide coating bysputtering from a metal target (or from a conductive, pressed oxidetarget) in an oxygen-rich atmosphere, or by DC sputtering from an oxidetarget, such as an indium oxide (IO), indium tungsten oxide (IWO),indium tin oxide (ITO) or indium cerium oxide (ICO) target or the like,such as described in PCT application No. PCT/US03/29776, filed Sep. 19,2003 by Donnelly Corporation et al. for MIRROR REFLECTIVE ELEMENTASSEMBLY, published Apr. 1, 2004 as International Publication No. WO2004/026633 A2, which is hereby incorporated herein by reference.However, other processes for applying or depositing layers of conductivematerial or layers and metallic material or layers may be implemented,without affecting the scope of the present invention.

The rear substrate 14 is masked substantially around the outer region ofsurface 14 a during the deposition process, such that thesemi-conductive and/or conductive layer or layers 20 is/are notdeposited in the masked outer region. However, substrate 14 is notmasked over the entire outer edge or region of substrate 14, in order toallow deposition of the layer or layers at a particular un-masked area,such that a tab-out portion or area 21 is formed in the layer or layers20. The tab out area 21 facilitates electrical connection of connector24 with the conductive layers 20.

As shown in FIG. 4, the upper edge 12 b of first or front substrate 12is formed to have a flattened area or relief area 12 d along a generallycentral region thereof. The relief area 12 d may be formed by cuttingthe glass substrate along the edge 12 b. The relief area 12 d allows theupper edge 12 b along the outer or side regions 12 e to generally alignwith the outer or side regions 14 e of upper edge 14 b of rear substrate14, while providing clearance at the center region 14 d of rearsubstrate 14 for the electrical connector or clip 24 to clip onto rearsubstrate 14 and coatings or layers 20. The relief area 12 d also formsa pocket that helps to contain the silicone material 23 (such asShin-Etsu 3421 or the like) which protects the tab out portion 21. Ascan be seen in FIG. 4, front substrate 12 is slightly larger than rearsubstrate 14, such that when the outer or side regions 12 e, 14 e ofupper edges 12 b, 14 b are aligned, the lower edge 12 c of frontsubstrate 12 extends downward below the lower edge 14 c of rearsubstrate 14, to provide for connection of the busbar 22 along loweredge 12 c of front substrate 12.

Because the relief area 12 d along upper edge 12 b of front substrate 12provides clearance for electrical connection to the other substrate 14,while also allowing for substantially flush alignment of the upper edges12 b, 14 b of the substrates 12, 14, the present invention provides forenhanced assembly processes for assembling the mirror element andobviates the need for a stepped or offset spacer or pin. During assemblyof the mirror element assembly 10, the substrates 12, 14 may be placedin a fixture with the outer regions 12 e, 14 e of the upper edges 12 b,14 b of both substrates abutting a wall of the fixture. The wall of thefixture thus aligns the upper edges of the substrates, and a stepped pinor the like is not necessary to provide the appropriate offset orclearance for the electrical connections to each substrate. This easesthe assembly process, since stepped pins do not have to be carefullyplaced at the appropriate places along the edges of the substrates toachieve the desired offset or clearance. Uniform pins may be placedbetween the substrates to provide the appropriate spacing or separationgap between the substrates during assembly.

Although shown and described as being generally aligned along the upperedges, the lower edges may alternately be aligned in a similar manner,without affecting the scope of the present invention. It is furtherenvisioned that a similar relief area may be formed at both the upperedge of one substrate and the lower edge of the other substrate, suchthat both the upper and lower edges may be generally flush or alignedwith one another, while providing clearance for electrical connection toboth substrates and their respective conductive or semi-conductive layeror layers.

Optionally, the first (outermost) surface 12 f of front substrate 12 maybe coated with an anti-wetting property, such as via a hydrophiliccoating (or stack of coatings), such as is disclosed in U.S. Pat. Nos.6,193,378; 5,854,708; 6,071,606 and 6,013,372, the entire disclosures ofwhich are hereby incorporated by reference herein. Also, the first(outermost) surface 12 f of front substrate 12 may be optionally coatedwith an anti-wetting property, such as via a hydrophobic coating (orstack of coatings), such as is disclosed in U.S. Pat. No. 5,724,187, theentire disclosure of which is hereby incorporated by reference herein.Such a hydrophobic property on the first/outermost surface of theelectrochromic mirror reflective elements (and on the first/outermostsurface of a non-electrochromic mirror, non-electro-optical,conventional reflective elements) can be achieved by a variety of meanssuch as by use of organic and inorganic coatings utilizing a siliconemoiety (for example, a urethane incorporating silicone moieties) or byutilizing diamond-like carbon coatings. For example, long-term stablewater-repellent and oil-repellent ultra-hydrophobic coatings, such asdescribed in PCT International Publication Nos. WO0192179 and WO0162682,the entire disclosures of which are hereby incorporated by referenceherein, can be disposed on the first (outermost) surface 12 f of frontsubstrate 12. Such ultra-hydrophobic layers comprise a nano structuredsurface covered with a hydrophobic agent which is supplied by anunderlying replenishment layer (such as is described in Classen et al.,“Towards a True “Non-Clean” Property: Highly Durable Ultra-HydrophobicCoating for Optical Applications”, ECC 2002 “Smart Coatings”Proceedings, 2002, 181-190, the entire disclosure of which is herebyincorporated by reference herein).

Referring now to FIG. 7, an electro-optic or electrochromic cell orreflective element assembly 110 for a rearview mirror assembly of avehicle includes a first or front substrate 112 and a second or rearsubstrate 114 (which typically are made of glass, but may comprise apolymeric material or the like), with an electrochromic medium 116disposed or sandwiched therebetween. The front substrate 112 includes anon-metallic, transparent semi-conductive layer 118 (such as indium tinoxide (ITO), doped tin oxide or the like, such as described in U.S. Pat.No. 6,002,511, which is hereby incorporated herein by reference)disposed on the rear or second surface 112 a, while the second or rearsubstrate 114 includes one or more metallic and/or non-metallicconductive or semi-conductive layers 120 (such as silver, silver alloyor other metal or metal alloy or the like) disposed on the front orinwardly facing or third surface 114 a of rear substrate 114. Theelectrochromic medium 116 is sandwiched between the semi-conductive orconductive layers 118, 120, and is contained therein via a seal 119positioned around the perimeter of the electrochromic medium 116. Theconductive or semi-conductive layers 118, 120, electrochromic medium 116and seal 119 may be substantially similar to the layers, electrochromicmedium and seal of mirror assembly 10, discussed above, such that adetailed description of these items need not be repeated herein.

As can be seen with reference to FIG. 7, reflective element assembly 110may comprise a generally flush cell or reflective element assembly, withat least some of the perimeter edges 112 b, 114 b of the substrates 112,114 being generally flush or aligned with one another. Electricalcurrent may be applied to each of the semi-conductive or conductivelayers 118, 120 via a respective pin or connecting member 122, 124 thatcontacts the respective semi-conductive or conductive layer and extendsrearwardly out the back or fourth surface 114 c of the rear substrate114 for electrical connection to an appropriate power source orcircuitry or control or the like at the rear of the electrochromic cellor reflective element assembly.

The first pin or connecting member 122 may be attached to the first orfront substrate 112, such as by counter sinking a head 122 a of pin 122into the rear surface 112 a of front substrate 112, such that a body orshaft portion 122 b of pin 122 extends rearward therefrom. The pin 122thus may contact (or may be contacted by) the semi-conductive layer orcoating 118 on the second surface 112 a of front substrate 112 to makethe electrical connection thereto. The pin may be countersunk in therear surface 112 a of front substrate 112 prior to depositing orapplying the semi-conductive layer 118 to the rear surface 112 a of thesubstrate 112. The substrate and pin assembly may then be placed in avacuum deposition chamber/apparatus, such as a sputter depositionchamber or the like, to have the semi-conductive coating 118 depositedon both the surface 112 a of substrate 112 and on at least a portion ofthe pin 122 itself. Such an approach provides an effective electricalconnection between the pin and the semi-conductive coating because thecoating is also deposited on and contacts the electrical connector orpin.

As can be see in FIG. 7, the pin 122 may be countersunk within the rearsurface 112 a of the front substrate 112 such that the head 122 a of thepin 122 is within the glass substrate and generally flush with thesurface 112 of the substrate. A metallic layer or coating or busbar 126may be applied around the perimeter region or surface of the substrate112 to enhance the electrical connection between the pin and the outerperimeter portion of the semi-conductive layer 118. The metallic layeror coating 126 may comprise an opaque metallic layer to conceal or hidethe seal 119 and electrical connectors and the like, so as to reduce thesize of the bezel overhang which may otherwise be needed to provide thedesired appearance of the perimeter edges of the mirror assembly.Optionally, the perimeter coating 126 may comprise a chromium oxide(often referred to as “black chrome”) or other metal or metal oxide ormetal compound that is dark, such as black, and thus effectively hidesor conceals the seal, connectors and the like, thereby obviating theneed for a bezel around the perimeter of the reflective elementassembly. The shaft portion 122 b of pin 122 may then extend through theseal and through a hole or aperture in the rear substrate 114. As can beseen in FIG. 7, the conductive coating 120 may not extend to the areawhere the pin 122 passes through rear substrate 114, such that anon-conductive glass surface or area or region 115 may be defined at theperimeter region of the surface 114 a of rear substrate 114. Thenon-conductive seal 119 may partially or substantially fill or encompassthe non-conductive area 115, such that the non-conductive area 115 andnon-conductive seal 119 electrically isolate or insulate the pin 122from conductive layer 120 of rear substrate 114.

Similar to pin 122, pin 124 may be countersunk within the front or thirdsurface 114 a of rear substrate 114, such that the head 124 a of pin 124is generally flush with the third surface 114 a of the substrate. Afterthe pin is countersunk within the rear substrate 114, the third surface114 a of the substrate may be coated with the semi-conductive layer orlayers, such that the semi-conductive layer 120 coats or contacts thehead 124 a of pin 124 and makes electrical contact therewith. The shaftor body portion 124 b of pin 124 may extend through a hole or openingthrough substrate 114 and rearwardly from the substrate or cell forelectrical connection to the appropriate power source or circuitry orcontrol or the like at the rear of the reflective element assembly. Ascan be seen in FIG. 7, the front or third surface 114 a of rearsubstrate 114 may be masked during coating of the third surface in thearea of the first pin 122, such that the conductive and/orsemi-conductive coatings or layers 120 are not applied to or depositedon the surface 114 a in the region where shaft 122 b of pin 122 extendsthrough substrate 114. This substantially precludes the possibility thatpin 122 may come in contact with both semi-conductive layers 118, 120,which may short the electrochromic cell or reflective element assembly.

The pin connectors of the electrochromic cell or reflective elementassembly of the present invention thus may facilitate a flushelectrochromic cell or reflective element assembly, because no clips orbusbars are required around the outside of the perimeter edges of thesubstrates to contact the semi-conductive and/or conductive layers ofthe substrates. Optionally, a perimeter coating, which may besubstantially opaque and may be conductive or semi-conductive, may beapplied along the perimeter regions or border of the semi-conductivelayer of the first or front substrate, in order to mask or hide orconceal the seal and connectors and the like to enhance the aestheticappearance of the electrochromic reflective element assembly and tominimize the size or overhang of the bezel of the mirror assembly. Theperimeter coating or layer may be of the type disclosed in U.S. Pat. No.5,066,112, which is hereby incorporated herein by reference, or may beany other type perimeter coating which may provide the desired result orappearance.

Referring now to FIG. 8, an electrochromic cell or reflective elementassembly 210 comprises a flush or generally flush electrochromicreflective element assembly and includes a front substrate 212 having ansemi-conductive coating or layer 218, and a rear substrate 214 having aconductive and/or semi-conductive coating 220, with an electrochromicmedium 216 disposed or sandwiched between the conductive orsemi-conductive layers 218, 220. An opaque or darkened or substantiallyopaquifying or hiding or concealing or light absorbing perimeter coating228 may be applied around the perimeter region or surface of thesemi-conductive coating 218 of front substrate 212 to mask or hide orconceal the seal 219 of the electrochromic reflective element assembly210. Perimeter coating 228 may comprise a black or darkened or opaquecoating (such as a substantially opaque or dark, such as black, coatingor layer) and may be conductive (such as a metallic electric conductivelayer or element) or a combined opaquifying or dark or blacknon-conductive layer closest to the substrate surface and a conductivelayer on the opaquifying layer. The perimeter coating may provide aclass A appearance (i.e. a surface readily viewable by a user of thevehicle and thus required to be aesthetically and functionallyacceptable) and may comprise a black ink or the like that may provide asubstantially uniform hiding and concealing layer which may be appliedvia an inkjet or screen print process or the like. If a non-conductiveopaque layer (such as paint or ink or the like) is used on the substratesurface, it is desirable to apply a conductive layer (such as aconductive tape or coating or the like) overt the opaque layer.Optionally, the opaquifying layer may comprise a chrome oxide (sometimesreferred to as “black chrome”), which may be substantially dark on thesurface, and may be coated with a substantially pure metal or chrome(such as discussed below with respect to FIG. 20) to provide aconductive layer or raceway along the substrate. Preferably, theopaquifying conductive coating or layer comprises a silver and aluminumalloy, but may comprise other dark colored (preferably black) conductiveinks and/or adhesives based on silver and/or silver alloys, such as anelectrically conductive black epoxy, such as EPO-TEK H32E or EPO-TEKH32C, both of which are available from Epoxy Technology of Billerica,Mass. It is further envisioned that other colors (other than black) maybe used for perimeter coatings an busbar hiding coatings to match thecolor of the mirror case or to match other desired colors or shades orthe like.

A metallic or conducting connector layer 230 may be applied or disposedor positioned around the perimeter region of the perimeter coating 228and may be folded or wrapped around to at least partially cover theperimeter edges 212 b of the substrate 212 so that an outer or edgeportion 230 a may extend partially along the outer perimeter edge 212 bof the substrate and may be in contact with the semi-conductive layerson the surface 212 a of substrate 212. As shown in FIG. 8, an outer oredge portion 220 a of the conductive layers 220 of rear substrate 214may also extend around or wrap around the outer perimeter edges 214 b ofrear substrate 214.

The outer or edge portions 230 a of the metallic layer 230 and the outeror edge portions 220 a of the layers or layers 220 of rear substrate 214thus may provide for electrical contact to the conductive layers of thesubstrate substantially around the perimeter of the electrochromic cellor reflective element assembly, without requiring overlap or offsetbetween the cells, such as for known or conventional clips and busbars.The metallic layer 230 and conductive layers 220 thus may provide anelectrical raceway around at least a portion of the reflective elementto enhance electrical flow along the substrates to enhance theperformance of the mirror cell. Optionally, the metallic layer 230 maybe substantially hidden by the Class A type appearance of the opaquelayer 228, such that the mirror cell or reflective element assembly mayminimize the size of any bezel associated with the mirror assembly,while providing an aesthetically pleasing mirror reflective element andmirror assembly. The reflective element assembly of the presentinvention thus may provide a minimum bezel size or no bezel mirror cellor reflective element assembly.

With reference to FIG. 9, an electrochromic cell or reflective elementassembly 210′ may be substantially similar to the electrochromic cell orreflective element assembly 210 shown in FIG. 8, and may include anouter wraparound connector 232, which may wrap around the perimeter ofthe reflective element assembly and provides for electrical contactbetween the metallic contacts or layers 230, 220 and the appropriatepower source, circuitry or control or the like. In the illustratedembodiment, wraparound connector 232 comprises an extruded flexiblemember which includes a wire connector 234. The wire connector 234extends along and through the wraparound connector 232 and connects tothe metallic connector 230, and may connect at the other end to theappropriate power source, circuitry or control or the like. Wraparoundconnector 232 also includes a second wire connector 236 which extendsthrough the wraparound connecter 232 and may connect the conductiveand/or semi-conductive layers 220 of the rear substrate 214 to theappropriate power supply, circuitry or control or the like. The extrudedwraparound connector 232 may be formed with the wires positioned orinserted therein and extending or protruding partially from anappropriate location or locations along the wraparound connector so asto make a strong electrical connection or contact with the respectivemember or layer when the wraparound connector 232 is wrapped around andsecured to the reflective element assembly 210′.

Similarly, as shown in FIG. 10, a wraparound connector 232′ may includea pair of electrical wires or metallic members 234′, 236′ extendingtherealong and partially protruding from an inner surface of theextruded wraparound connector 232′. One of the wires or members 234′ maypartially protrude along the inner surface of the connector to contactthe outer or edge portion 230 a of the metallic layer or connector 230to make electrical connection thereto at least partially orsubstantially around the perimeter of the front substrate 212 of theelectrochromic cell or reflective element assembly 210″. Likewise, theother wire or metallic member 236′ may protrude partially from theextruded wraparound connector 232′ to contact the outer or edge portion220 a of the layer or layers 220 along the outer perimeter edge of therear substrate 214 to make electrical connection thereto at leastpartially or substantially around the perimeter edge or edges of therear substrate. One or more electrical wires or connectors may extendthrough the wrap around connector 232′ to contact the appropriate one ofthe wires or metallic members 234′, 236′, in order to provide electricalconnection to between the wires 234′, 236′ and the appropriate powersource, circuitry or control or the like at the rear of the reflectiveelement assembly.

Although shown as having a single perimeter electrical connector orlayer 230 along the second surface of the front substrate 212, thereflective element assemblies 210′, 210″ may optionally include asubstantially opaque Class A layer between the connectors 230 andsemi-conductive layer 218, such as described above with respect to thereflective element assembly 210 of FIG. 8. Optionally, the electricalconnectors 230 may comprise an opaque conductive material and mayprovide a black or opaque appearance to hide or conceal the seal 219 andconnectors of the reflective element assemblies, such as via utilizingprinciples disclosed in U.S. Pat. No. 5,066,112, which is herebyincorporated herein by reference.

Referring now to FIGS. 11 and 12, a flush electro-optic orelectrochromic cell or reflective element assembly 310 for an exteriorrearview mirror assembly of a vehicle comprises a front substrate 312and a rear substrate 314. The reflective element assembly 310 alsoincludes semi-conductive and/or conductive layers and electrochromicmedium (not shown in FIGS. 11 and 12), such as described above or suchas otherwise known in the art. As can be seen in FIGS. 11 and 12, bothof the substrates 312, 314 are cut in a wave like pattern, such as asine wave or the like, around the perimeter edges of the substrate, withthe wave cut of the rear substrate 314 being about 180 degrees out ofphase with the wave cut of the front substrate 312. When the substratesare generally aligned with one another, the waves are out of phase andprovide alternating outward peaks for connection of an electricalconnector at least substantially around the entire perimeter of thesubstrates and reflective element assembly.

The front and rear substrates of the reflective element assembly thusmay have a full wraparound busbar connected at least some of or most ofor each of the outer points or peaks of the waves. As shown in FIG. 12,a clip or busbar 338 for providing electrical connection to the outwardprotrusions or peaks of the respective one of the substrates may includea plurality of clips or clip portions 338 a connected together by aconnecting member 338 b. The spacing between the clips 338 a generallycorresponds to the wavelength of the wave cut around the substrates.Although only one of the clips or busbars for the rear substrate 314 isshown in FIG. 12, the other clip or busbar for the front substrate 312would be substantially similar to busbar 338, but with the clipsaligning with the outward peaks or protrusions or wave portions of thewave cut around the front substrate. The clips may connect to or contactconductive layers or busbars or raceways (not shown in FIGS. 11 and 12)that are disposed along the perimeter edge of the substrate. The wavedesign or pattern may vary depending on the size and particularapplication of the mirror assembly, the conductivity of thesemi-conductive and/or conductive coatings on the substrates, and/or thelike. For example, the wave cut may change in amplitude and/or frequencydepending on the particular application. The clips or busbars may alsochange to correspond with the changes in the wave profile.

The wave cut reflective element assembly or electrochromic cell mayprovide a faster coloring of the reflective element assembly orelectrochromic cell and a more uniform transition from bleached to colorbecause the electrical potential may be generally uniformly distributedat substantially all of the points along the perimeter of the reflectiveelement assembly. The benefits associated with the wave cut design maybe even more significant for larger mirror sizes. The wave cut design ofthe present invention may also facilitate implementation of a lessexpensive or lower conductivity substrate while having little or noaffect on the performance of the reflective element assembly orelectrochromic cell. The cell gap may thus also be made smaller toassist in reducing double imaging of the mirror assembly. Also, becausethe voltage may be distributed more uniformly across the electrochromiccell, the “banding effect” may be significantly less for the wave cutdesign. Because the electrochromic cell may be a generally flushelectrochromic cell, multiple cells may be stacked on one another duringthe manufacturing process using less complicated and less costlyfixtures and jigs, in order to reduce the manufacturing costs associatedwith the electrochromic cells. Also, by taking advantage of theoverlapping areas of the substrates, the effective surface area of theperimeter seal around the electrochromic cell may be made larger than inconventional cells.

Referring now to FIGS. 13-15, a one sided flush electro-optic orelectrochromic cell or reflective element assembly 410 includes a frontsubstrate 412 and a rear substrate 414. The reflective element assembly410 also includes an electro-optic or electrochromic medium andconductive and/or semi-conductive layers or coatings, which may besubstantially similar to the elements of the reflective element assembly10 of FIGS. 4-6, discussed above. As shown in FIG. 13, the frontsubstrate 412 may comprise a substantially oval shaped substrate and maybe downwardly offset with respect to the rear substrate 414, such thatthe lower edge 412 b of the front substrate 412 extends over and belowthe lower edge 414 b of the rear substrate 414 to facilitate electricalconnection thereto. The rear substrate 414 is formed to have an upwardlyextending portion or top hat portion 414 c along the middle region ofthe upper edge of the substrate 414, such that the upward extendingportion 414 c is generally offset from the upper edge 412 c of frontsubstrate 412, while the side portions or regions of the upper edges ofthe substrates are generally flush or aligned with one another.

The upward extending portion or top hat portion 414 c of rear substrate414 thus may provide or facilitate electrical connection to the rearsubstrate, without requiring the substrates to be offset along the upperedges in the conventional manner. As shown in FIG. 14, the conductivecoating 420 on the third surface of the rear substrate 414 may include atab out portion 420 a for the electrical connector to connect thereto.The upward extending portion or top hat portion 414 c of the rearsubstrate 414 thus may provide for electrical connection to theconductive coatings on the rear substrate, while also providing for asubstantially flush upper edge along a substantial portion of the upperedges of the reflective element assembly, such that offset pins and thelike are not required during the manufacturing processes of theelectrochromic cell or reflective element assembly 410. A seal 419 (FIG.15) may be provided around the perimeter region or surface of the rearsubstrate 414 to encase or seal the electrochromic medium, such asdiscussed above.

Referring now to FIGS. 16-19, an electro-optic or electrochromic cell orreflective element assembly 510, such as for an interior or exteriorrearview mirror assembly of a vehicle, includes a front substrate 512and a rear substrate 514, with an electro-optic or electrochromic medium516 (FIGS. 17 and 19) disposed or sandwiched therebetween. Frontsubstrate 512 includes an opaquifying or darkening or hiding conductivecoating or layer 519 (such as, for example, an opaque or blackconductive epoxy or dark colored conductive frit or chromeoxide/metallic chrome bilayer or the like, or other materials such asdescribed above with respect to layer 228) applied or deposited aroundthe border or perimeter of the front substrate 512. The opaquifyinglayer 519 may at least partially wrap around the perimeter edges of thesubstrate so that an edge portion 519 c of opaquifying layer 519 extendsat least partially along the perimeter edge 512 c of substrate 512. Thefront substrate 512 also includes a semi-conductive, transparent coatingor layer 518 (such as an ITO layer or doped ITO layer or the like)applied to or deposited on the rear surface 512 a of front substrate 512and overlapping the opaquifying or hiding conductive border layer orcoating 519 (as can be seen with reference to FIG. 17). Alternately, thesemi-conductive layer 518 may be applied to or deposited on the rearsurface 512 a of front substrate 512 first, and then the opaquifying orblack conductive layer may be applied to or deposited on the perimeterregion of the semi-conductive layer 518. The conductive layer 519provides an electrical raceway (due to the lower resistance provided bythe conductive layer 519 versus the semi-conductive or ITO layer 518)around the perimeter of and in contact with the semi-conductive layer518 to provide quick electrical flow around the perimeter of thesemi-conductive layer to quickly energize the layer and getsubstantially uniform and even and rapid coloring or darkening of thereflective element assembly.

The rear substrate 514 includes a metallic or conductive layer orcoating 520, preferably a highly reflective metallic layer or coating(such as, for example, chromium, chromium/rhodium, silver, aluminum,silver alloy, aluminum alloy, ITO/silver/ITO stack, ITO/aluminum/ITOstack (such as ITO-silver-ITO stacks, display on demand stacks orinfrared transmitting stacks of the types disclosed in PCT applicationNo. PCT/US03/29776, filed Sep. 19, 2003 by Donnelly Corporation et al.for MIRROR REFLECTIVE ELEMENT ASSEMBLY, published Apr. 1, 2004 asInternational Publication No. WO 2004/026633 A2, which is herebyincorporated herein by reference) or the like) applied to or depositedon and substantially over the third surface 514 a of rear substrate 514.The outer perimeter edge area or border region 514 b of the thirdsurface 514 a of the rear substrate 514 may be masked while the metallicreflector 520 is applied, such that the border region 514 b of the frontsurface 514 a of substrate 514 provides a non-conductive surface or pathor raceway 514 e (such as a glass surface or the like) at leastpartially around the metallic reflector 520 and proximate to the edge514 d of substrate 514.

As shown in FIG. 16, rear substrate 514 may also include a conductivecoating or layer 521 (such as, for example, a conductive epoxy layer ora conductive silver frit layer or the like) applied to or deposited onor positioned at and partially along a perimeter edge 514 d of thesubstrate 514 (optionally, a third surface portion 521 a of theconductive layer 521 may extend partially along the border region 514 bof the third surface 514 a, or the conductive layer 521 may have an edgeportion 521 c that may partially wrap around and onto and over the edge514 d of substrate 514, or the conductive layer 521 may further includea rear portion 521 b (FIG. 18) that may extend or wrap further around tothe rear or fourth surface 514 c of substrate 514). A tab out portion520 a of conductive layer 520 may extend over the border region 514 b orraceway 514 e and may overlap the conductive coating 521 to provide anelectrical contact point or region or area for the rear substrate 514,as discussed below. The non-conductive raceway 514 e thus issubstantially devoid of the conductive layer 520 except at the tabportion. Optionally, the tab out portion 520 a may wrap at leastpartially around the edge dimension 514 d of the substrate 514 (such asshown in FIG. 16, where the tab out portion 520 a extends along an outerperimeter or border region 514 b of third surface 514 a of substrate 514and may further extend at least partially along and over the perimeteredge 514 d of substrate 514 and over edge portion 521 c of conductivecoating 521).

As shown in FIG. 17, the front substrate has a height dimension that isgreater than a corresponding height dimension of the rear substrate,such that the upper perimeter region or edge portion 512 f and lowerperimeter region or edge portion 512 g of front substrate 512 extendbeyond the corresponding perimeter regions or edge portions 514 f, 514 gof rear substrate 514 and define upper and lower overhang regions 512 h,512 i. The connector or connectors may connect to the conductive layerat the rear surface of the front substrate at the overhang region orregions 512 h, 512 i and thus may not interfere or overlap the perimeteredge of the front substrate. The overhang regions of the front substraterelative to the rear substrate thus may allow for the electricalconnectors to connect to the respective conductive layers substantiallyor entirely within the viewable profile of the front substrate byextending along the respective perimeter edges of the rear substrate,such that the connectors do not overlap the perimeter regions of thefront substrate and, thus, are not viewable at the front surface of thefront substrate. The front substrate may include a hiding layer orconcealing layer at the perimeter regions or overhang regions, such asat the rear surface of the front substrate, to substantially hide orconceal the connectors and the seal of the reflective element assembly.The reflective element assembly thus may be suitable for a bezelless orminimal bezel mirror assembly.

Although shown and described herein as having upper and lower overhangregions, the reflective element assembly of the present invention mayhave only one overhang region, such as for the electrical connection tothe conductive layer on the rear surface of the front substrate, or mayhave one or more overhang regions elsewhere along the perimeter of thereflective element assembly, such as along one or both sides of thereflective element assembly or the like, without affecting the scope ofthe present invention. The overhang region or regions may be selected atthe upper or lower edges or at one or both side edges of the reflectiveelement assembly depending on the particular application of thereflective element assembly. For example, for an interior rearviewmirror assembly, where the longitudinal axis of the reflective elementassembly typically extends lengthwise along the reflective elementassembly (such as generally horizontally when the reflective elementassembly is installed in a vehicle), the overhang region or regions maybe at the upper and/or lower edges of the reflective element assembly.Similarly, for an exterior mirror assembly of, for example, a truck orthe like, where the longitudinal axis of the reflective element assemblymay extend generally vertically when the reflective element assembly isinstalled at the truck or vehicle (in other words, where the width ofthe reflective element assembly is less than the height of thereflective element assembly), the overhang regions may be at the sideedges of the reflective element assembly. The overhang regions may thusextend along the width dimension of the reflective element assembly.However, the overhang regions may be elsewhere along or around the edgesof the reflective element assembly, without affecting the scope of thepresent invention.

As can also be seen with reference to FIG. 17, reflective elementassembly 510 may provide an electrically conductive opaque or hiding orconcealing layer 519 at least substantially around the perimeter edgesof the front substrate, with the transparent semi-conductive layer 518overlapping the opaque conducting layer 519 in the area at which theseal 517 is positioned around the electrochromic medium 516. The opaqueconducting layer 519 thus provides a contacting region around theperimeter of the substrate for contacting the transparentsemi-conductive layers or coatings 518. The seal 517 is positioned alongthe opaque conductive layer 519 and is thus masked or hidden by theopaque conductive layer to enhance the appearance of the reflectiveelement assembly, particularly when the electro-optic or electrochromicmedium is darkened or colored. The opaque conductive layer may thusallow for a smaller or no bezel overhang around the perimeter of thereflective element assembly. As can be seen in FIGS. 17 and 19, the seal517 may be positioned around the masked or border region 514 b of therear substrate 514. The non-conductive perimeter seal 517 at leastpartially fills or covers or encompasses the non-conductive glasssurface or masked region 514 e to electrically isolate or insulate theconductive coating 520 from the conductive adhesive 526, such that theconductive coating 520 of rear substrate 514 is electrically isolatedfrom connector 522 that connects to the conductive surface 518 of frontsubstrate 512.

As shown in FIGS. 18 and 19, the front substrate 512 and rear substrate514 may include electrical connectors or terminals 522 and 524,respectively, for providing electrical connection to the conductive orsemi-conductive layers 518, 520. Particularly, and as shown in FIG. 18,rear substrate 514 may include an electrical connection terminal orconnector 524 at its rear or fourth surface 514 c for providingelectrical connection between the conductive metallic layer 520 and theappropriate electrical source, circuitry or control or the like at therear of the reflective element assembly. The electrical connectionterminal 524 may be soldered or adhered or attached (such as viaelectrically conductive adhesive or the like, such as a conductivecoating or layer or the like) to, or may be mechanically contacting at(such as via a spring-action contact or the like) a rear portion 521 bof the conductive coating or layer 521 along the fourth or rear surface514 c of rear substrate 514. The conductive layer 521 thus provideselectrical connection between the terminal 524 at the rear or fourthsurface 514 c of rear substrate 514 and the conductive layer 520 at thefront or third surface 514 a of rear substrate 514.

As discussed above, the electrically conductive layer 521 may provideelectrical connection to the metallic reflector 520 via the tab-outportion 520 a of the metallic reflector, which may be overcoated orapplied to the front portion 521 a of the electrically conductive layer521 along the front or third surface 514 a of the rear substrate 514. Apotting material 526 (such as, for example, a silicone or urethaneelastomer, preferably a conductive semi-elastomeric material or thelike) may be applied or positioned over the rear surface (and may beapplied partially or entirely around the outer perimeter edge of thesubstrate) to seal the connection of the connector terminal 524 and theconductive layer 521. The electrical connection terminal 524 may extendrearward from the reflective element assembly 510 and may protrude fromthe potting material 526 for electrical connection to a connectorassociated with the appropriate electrical power, circuitry or controlor the like.

As shown in FIG. 19, the front substrate 512 of reflective elementassembly 510 may include one or more electrical connection terminals 522at or along its rear or second surface 512 a. The electrical connectionterminal 522 may comprise a stick or ribbon or pin connector forproviding electrical connection to the semi-conductive transparent layer518 at the second surface 512 a of front substrate 512 and generally ator along the lower overhang region 512 i. The electrical connector orterminal 522 may be positioned entirely within a perimeter profile (asviewed from the front of the reflective element assembly) of the frontsubstrate and generally rearward of the overhang region, so that theelectrical connector or terminal is substantially not viewable throughthe front surface of the front substrate. The electrical connectionterminal 522 may be soldered or adhesively attached, such as via anelectrically conductive epoxy or the like, to the semi-conductive layer518, or may be mechanically attached to or contacting thesemi-conductive layer 518, such as via a spring-action contact or thelike, and may extend or protrude rearward from the front substrate (andmay extend rearward of the rear substrate as shown in FIG. 19) forelectrical connection to the appropriate electrical power, circuitry orcontrol or the like at the rear of the reflective element assembly.

As discussed above, the semi-conductive layer 518 may be applied to ordeposited on the second surface 512 a of substrate 512 and on or over aperimeter black out or opaquifying layer 519. Optionally, as alsodiscussed above, the perimeter layer 519 may be conductive. Optionally,as shown in FIG. 19, the perimeter opaquifying layer 519 may benon-conducting and applied to or deposited on the outer perimeter region512 g of the rear surface 512 a of front substrate 512, and anelectrical conducting perimeter busbar layer 519 a (such as a metallicor high electrical conducting layer) may be applied to the opaquifyinglayer 519 and may overlap or fold over to cover a portion of the sideedge 512 c of substrate 512, such that the metallic or high electricalconducting busbar layer 519 a may provide the electrical connection tothe semi-conductive layer 518, while the opaquifying layer 519 mayfunction to substantially hide or conceal the metallic busbar layer 519a and seal 517 of the reflective element assembly, such that the layersand seals and connectors are not viewable by a driver or occupant of thevehicle when viewing the reflective element assembly of the mirrorassembly of the vehicle.

The potting material 526 may extend partially around the perimeter edgeof the front substrate and substantially surround and seal theelectrical connector 522 at the rear surface of the front substrate.Preferably, the material 526 surrounding the connector 522 may comprisea conductive material, such as a conductive epoxy, such as a conductiveepoxy commercially available from DuPont, a conductive paste, aconductive tape, such as a copper tape with conductive adhesive, aconductive frit or the like, to provide an enhanced connection of thepin or connector 522 to the conductive layer or raceway and thesemi-conductive or ITO layer or the like on the front substrate. Asshown in FIG. 19, the connector 522 may contact the semi-conductivelayer 518 at the conductive busbar layer 519 a, and the conductivematerial 526 may substantially surround the connector 522 to enhance theelectrical connection between the connector and the semi-conductivelayer 518 and/or the conductive busbar layer 519 a. Optionally, and withreference to FIG. 19A, the connector 522′ may be spaced from thesemi-conductive layer 518 and conductive busbar layer 519 a andsubstantially surrounded by the conductive material 526, such that theconductive material 526 connects the connector 522 along thesemi-conductive layer 518 and busbar layer 519 a. Because a substantialamount of conductive material 526 may be packed in or disposed aroundthe connectors and along the semi-conductive layer and busbar layer tosubstantially fill the overlap region or area, the conductive materialmay provide enhanced electrical flow and electrical contact between theconnector and the busbar layer, thereby improving the performance of thereflective element assembly. Therefore, the conductive material mayprovide a substantial raceway effect along the semi-conductive layer andbusbar layer even if the conductive material is a weak conductor.

The conductive material or epoxy may be injected or disposed into thearea of the reflective element assembly outside and around the perimeterseal to substantially fill the area and to enhance the conductivityaround the connector 522 and conductive coating 518 of front substrate512. Optionally, the conductive material or epoxy may be applied to theoverlap region at the “empty cell” stage of the manufacturing process,where the cell has not yet been filled with the electrochromic medium.The empty cell, with the seal and conductive epoxy disposed thereon, maythen be fired or heated together to cure or harden both the seal and theconductive epoxy in a single process.

Therefore, the opaquifying layer and semi-conductive and conductivelayers, and the electrical connectors of the reflective element assembly510 provide a concealed or hidden seal and electrical connectors, suchthat the bezel size may be reduced or eliminated, while providing anaesthetically pleasing rearview mirror assembly and reflective element.The overhang region of the front substrate relative to the rearsubstrate may allow for multiple electrical connectors or multiple-pointcontact between the front electrical/perimeter busbar and theappropriate electrical power or circuitry or control or the like at therear of the reflective element assembly or cell.

Optionally, and as shown in FIG. 20, the rear or second surface 512 a′of a front substrate 512′ may include multiple hiding layers 519′ aroundthe perimeter regions (such as lower perimeter region 512 g′ of FIG. 20)of the substrate to conceal or hide the seal 517 and connectors (notshown in FIG. 20) of the reflective element assembly. For example, thehiding layers 519′ may include a “black chrome” layer 519 a′ (such as achromium oxide layer or the like) applied to or deposited on the rearsurface 512 a′ of the substrate and along the perimeter regions andoverhang regions, and a chromium metal layer 519 b′, which may besputter deposited or otherwise applied to the layer or layers ofchromium oxide 519 a′. Alternately, other metals or metal compounds maybe deposited on the perimeter regions of front surface 512 a′ of frontsubstrate 512′, and preferably may be applied in a manner that resultsin a substantially opaque layer (that may be substantiallynon-conductive) at the surface of the substrate and a substantiallypure, highly conductive metallic layer over the opaque layer, such asdiscussed below.

The coatings or layers on the second surface 512 a′ of substrate 512′may be applied to or deposited on the second surface in a manner toprovide multiple and varying layers of chromium oxide or other metals ormetal compounds or the like to enhance the performance of the layers.For example, the central region of the second surface 512 a′ may bemasked while leaving the border or perimeter region 512 b′ unmaskedduring the application or deposition of the layers 519′. The chromiumoxide layer or layers 519 a′ or the like may be reactively sputterdeposited or evaporated in an oxygen atmosphere to deposit a dark, lightabsorbing chromium layer on the perimeter region 512 b′ of the secondsurface 512 a′ of the front substrate 512′. While the chromium oxide isbeing deposited or applied to the perimeter region 512 b′, the oxygengas level in the vacuum chamber may be gradually reduced toapproximately zero, thereby providing varying layers 519 a′ of chromiumoxide on the perimeter region 512 b′. The chromium metal conductivelayer 519 b′ may then be sputter deposited or coated onto the chromiumoxide layer or layers 519 a′, such as in a zero oxygen atmosphere, todeposit a metal conducting perimeter coating at the perimeter region 512b′ of the rear surface 512 a′ of front substrate 512′. The frontsubstrate 512′ may be removed from the vacuum chamber and the mask overthe central region may be removed. The transparent semi-conductivecoating or layer 518 may then be sputter deposited or coated orotherwise applied to or deposited on or across the entire rear surface512 a′ of front substrate 512′. Such a process and coatings provide abuild up of “black chrome” (such as approximately 500 angstroms toapproximately 2,000 angstroms thick) initially, followed by “metallicchrome” (such as approximately 500 angstroms to approximately 3,000angstroms thick), thereby forming a border or perimeter electricallyconductive busbar, but with the black chrome layer being substantiallynon-reflecting when viewed from the first surface side of the frontsubstrate or reflective element assembly. Although described ascomprising chrome oxide, other metals may be provided to form a metalcompound (such as chrome oxide, nickel oxide, silver oxide or the like)at the substrate surface and a substantially pure metallic deposit (suchas chromium, nickel, silver or the like) to provide a highly conductiveraceway. The metal compound may be sandwiched between the substrate andthe substantially pure metal, and provides a dark (such as black) layerat the substrate surface to at least substantially conceal or hide theseals and connectors and the like, while the substantially pure metal isat the semi-conductive layer or ITO layer or the like.

Optionally, and according to another aspect of the present invention, anelectro-optic or electrochromic mirror assembly for a vehicle maycomprise an electro-optic or electrochromic mirror element or reflectiveelement assembly comprising a front or first substrate having first andsecond surfaces and a rear or second substrate having third and fourthsurfaces. The first and second substrates are arranged so that thesecond surface opposes the third surface with an electro-optic orelectrochromic medium disposed therebetween. The first substrate has atleast one at least partially conductive or semi-conductive coating orlayer on the second surface and may also have an opaquifying conductiveborder/perimeter coating/layer around the perimeter edges or regions ofthe substrate. The second substrate has at least one at least partiallyconductive coating or layer on the third surface. The first and secondsubstrates are positioned relative to one another such that at least aportion of an edge of the first substrate is generally flush or alignedwith a corresponding edge of the second substrate. The edge of thesecond substrate may have a relief area formed therealong relative tothe edge of the first substrate, wherein the relief area providesclearance or access for electrical connection to the conductiveborder/perimeter coating/layer on the second surface of thecorresponding edge of the first substrate. The electrical connections tothe first substrate may provide or deliver electrical power to thesemi-conductive coating on the second surface of the first substrate andto the conductive coating on the third surface of the second substrate,as discussed below.

The perimeter seal of the reflective element assembly may be formed suchthat the outer edge of the perimeter seal is generally flush with theedges of both the first and second substrates except in the relief areaor areas formed along the edge of second substrate. The perimeter sealprofile in the relief areas along the edge of the second substrate maybe configured such that the outer edge of the perimeter seal is recessedfrom the outer edges of both the first and second substrates, such thata gap or spacing between the first and the second substrates is createdoutside of the seal. A conductive material or bridge may be disposed orapplied at the gap or spacing to couple the conductive coating on thethird surface of the second substrate with the appropriate electricalconnector or contact at the border/perimeter conductive coating/layer onthe second surface of the first substrate. In addition, in order toavoid shorting of the positive and negative electrical contacts, a smallportion of the border/perimeter conductive coating/layer and theunderneath transparent semi-conductive coating on the second surface ofthe first substrate may be removed (electrically isolated) in a patterngenerally around the electrical contact for the second substrate at thespacing created in the relief area or areas formed along the edge oredges of the substrates. Electrical contact to the semi-conductive layerof the second surface of the first substrate may be made by affixing anelectrical lead to the perimeter/border conductive coating/layer in therelief areas, while electrical contact to the third surface of thesecond substrate may be made by affixing an electrical lead to theperimeter/border conductive coating/layer of the first substrate in theelectrically isolated portion of the relief area or areas. Theelectrical contact is then made to the third surface of the secondsubstrate via the conductive material or bridge between the first andsecond substrates at the electrically isolated relief area or areas.

The electrical contacts to the transparent semi-conductive layer on thefront substrate and the reflective conductive layer on the rearsubstrate may thus be made at one of the substrates, with a conductivebridge connecting one of the contacts at one substrate to the coating orlayer on the other substrate. Such a configuration or arrangement mayprovide for a true flush, bezelless cell or reflective element assemblyand may facilitate making both electrical contacts to the frontsubstrate at specified areas or relief areas along the perimeter edgesor regions of the substrates.

For example, and with reference to FIG. 21, an electro-optic orelectrochromic reflective element assembly or cell 610 includes a frontsubstrate 612 and a rear substrate 614 and may provide generally flushedges of the substrates substantially around the reflective elementassembly. As shown in FIG. 21, the front substrate 612 may provide a tophat form or protrusion 612 c along the upper edge of the frontsubstrate, and the rear substrate 614 may also provide a smaller top hatform or protrusion 614 c along its upper edge (such as discussed abovewith respect to the rear substrate 414 of FIGS. 13-15). The seal aroundthe electrochromic medium is positioned along and between the outeredges of the substrates, except at the top hat forms. The top hat form614 c of rear substrate 614 thus generally overlaps the top hat form 612c of front substrate 612, with a gap or spacing defined between the tophat forms 612 c, 614 c and outward of the seal.

The second surface or rear surface of front substrate 612 is coated witha semi-conductive transparent coating or layer and a perimeter busbarlayer 619 a and perimeter opaquifying or “black-out” layer 619 aroundits perimeter edges, such as, for example, coatings or layers similar tothe busbar layer 519 a and opaquifying layer 519 of reflective elementassembly 510, discussed above. As can be seen in FIG. 21, the top hatform 612 c of front substrate 612 provides for electrical contacts orconnectors 622 (such as pins or clips or the like) at the perimeterbusbar layer 619 a at either or both ends of the top hat form 612 c. Agap or deletion line 621 may be provided along a portion of theconductive layer on top hat form 612 c to electrically isolate a centerportion or region 621 a of the top hat form 612 c from the ends of thetop hat form where the positive electrical contacts are provided. Anelectrical contact or connector 624 (such as a pin or clip or the like)may be provided at the electrically isolated region 621 a.

Top hat form 614 c of rear substrate 614 may be coated with theconductive coating on the third surface of the substrate and/or may havea conductive coating or layer and tab-out edge of the conductive coatingon the surface (such as, for example, a conductive coating or layer andtab-out portion of the types described above with respect to FIG. 16).The second or rear substrate 614 may include a perimeter, electricallyconductive coating or layer around the perimeter edges and perimeterregions of the third surface of the rear substrate 614 (such as, forexample, a perimeter electrically conductive coating of the typedescribed above with respect to FIG. 18).

Reflective element assembly 610 further includes a conductive materialor bridge 623, such as a conductive epoxy or the like, disposed at theelectrically isolated region 621 a and spanning the gap between the tophat forms 612 c, 614 c of the front and rear substrates. The conductivebridge 623 provides for electrical connection between the electricallyisolated region 621 a (and the electrical connector 624 connectedthereto) of the top hat form 612 c of front substrate 612 and theconductive coating or layer or tab-out region of the top hat form 614 cof rear substrate 614.

Accordingly, electrical power may be applied to the semi-conductivecoating or layer on the second surface of the front substrate via anelectrical connector or contact (such as a pin or clip or the like) atthe top hat form of the front substrate. Electrical power may also beapplied to the conductive coating or layer on the third surface of therear substrate via an electrical connector or contact (such as a pin orclip or the like) also positioned at the top hat form of the frontsubstrate (and via the conductive bridge). The present invention thusprovides a flush electro-optic or electrochromic cell or reflectiveelement assembly with electrical contacts at only one of the substrates.

Optionally, and with reference to FIGS. 22 and 23, an electro-optic orelectrochromic mirror cell or reflective element assembly 610′ mayprovide one or more relief regions 625 around the perimeter edges of thereflective element assembly, such as at generally opposite corners ofthe reflective element assembly 610′. The relief regions 625 may bedefined by areas or regions of the rear substrate 614′ which may be cutback relative to the corresponding edge or edges of the front substrate612′ to provide a relief area exposing the second surface of the frontsubstrate 612′ when the reflective element assembly is viewed from therear of the reflective element assembly. The front and rear substrates612′, 614′ may otherwise be generally flush along their edges except atthe relief regions 625.

The front substrate 612′ may include a transparent semi-conductive layeron its second or rear surface and may include a busbar layer 619 a′(which may include a tab out portion 619 b′ over the relief region orregions 625) and/or a opaquifying or black-out layer around itsperimeter edges and an electrical contact 622′ at each of the areas orregions exposed by the relief regions (such as discussed above). Theelectrical contact 622′ is electrically connected to the semi-conductivelayer and busbar layer or tab out portion on the front substrate 612′.Each of the areas or regions of the second surface of the frontsubstrate that are exposed by the relief regions also includes adeletion line 621′ that defines an electrically isolated area or region621 a′. A second electrical contact 624′ is applied or connected to theelectrically isolated region 621 a′ of each of the relief regions.

As can be seen in FIGS. 22 and 23, the seal 617′ around theelectro-optic or electrochromic medium of the reflective elementassembly may be configured or arranged to be between the front and rearsubstrates and generally along the perimeter edges of the front and rearsubstrates, except in the relief regions 625. At the relief regions 625,the seal may be positioned inward of the outer edges 614 c′ of the rearsubstrate 614′, which are inward of the outer edges 612 c′ of the frontsubstrate 612′. A gap or spacing thus exists between the front and rearsubstrates outside of the seal 617′ and at each of the relief regions625. The electrically isolated region 621 a′ is formed to generallycorrespond with the area of the substrates that have the gap or spacingtherebetween. A conductive material or bridge 623′ is provided betweenthe front and rear substrates at each of the relief regions toconductively span the gap between the electrically isolated area 621 a′(and electrical connector 624′) of the front substrate 612′ and theconductive coating or layer or layers of the rear substrate 614′.

Optionally, and as shown in FIG. 24, the reflective element assembly610″ may include a perimeter conductive coating or busbar coating 619 a″around the perimeter of the front substrate 612′ and a seal 617″ aroundthe perimeter of the substrates except at the relief region 625″ of therear substrate 614″. In the illustrated embodiment of FIG. 24, theelectro-optic or electrochromic reflective element assembly includes onerelief region 625″ (defined by the cut off or reduced edge 614 c″ ofrear substrate 614″), but could include two or more, such as at oppositecorners of the reflective element assembly or the like, withoutaffecting the scope of the present invention. The reflective elementassembly 610″ is otherwise substantially similar to reflective elementassembly 610′, discussed above, such that a detailed discussion of thereflective element assembly will not be repeated herein.

The electro-optic or electrochromic mirror cell or reflective elementassembly 610′ thus may provide for electrical connections at two or morelocations around the mirror cell or reflective element assembly, and mayprovide for the electrical connections at only the front substrate ofthe reflective element assembly. The reflective element assembly thusmay provide a flush reflective element assembly or mirror cell that maybe implemented in a bezelless mirror assembly, while providing enhancedperformance or coloring or darkening of the reflective element assembly.

Optionally, and with reference to FIGS. 25A and 25B, an exteriorrearview mirror cell or reflective element assembly for an exteriorrearview mirror assembly of a vehicle includes a first or frontsubstrate 712 (FIG. 25A) and a second or rear substrate 714 (FIG. 25B)and an electro-optic or electrochromic medium and seal 717 sandwichedtherebetween, such as described above. As also described above, thefront substrate 712 may have a transparent semi-conductive layer orcoating 718 (such as ITO or the like) applied to the second or rearsurface 712 a of the substrate, and may include an opaquifyingconductive border/perimeter coating or layer 719 (such as, for example,a black conductive epoxy or dark colored conductive frit or blackchrome/metallic chrome layer or the like) applied around the perimeteredges of the front substrate 712. As shown in FIG. 25A, the perimetercoating or layer 719 may be along the perimeter edges of the frontsubstrate 712 except in an electrical connection area or region 725 ofsubstrate 712, where the perimeter coating 719 is inward of the outeredges of substrate 712. The electrical connection region 725 is coatedby the semi-conductive layer 718 and/or a conductive layer or the like.A deletion line 721, such as a non-conductive area in the region 725where the busbar layer and semi-conductive layer is etched off orotherwise removed from or not applied to the surface of the substrate,is formed at the electrical connection area 725 to separate and defineand electrically isolate a rear substrate electrical connection area 725a or raceway portion of the semi-conductive layer from a front substrateelectrical connection area 725 b or surface portion of thesemi-conductive layer.

An electrical connection or contact 722 is connected to or applied tothe front substrate electrical connection area 725 b to provideelectrical power or connection to the semi-conductive layer 718 on therear surface of the front substrate 712. Likewise, an electricalconnection or contact 724 is connected to or applied to the electricallyisolated rear substrate electrical connection area 725 a and is inelectrical communication with the conductive layer of the third surface714 a of rear substrate 714 via a conductive material or bridge 723, asdiscussed below.

With reference to FIG. 25B, rear substrate 714 includes a metallicreflector layer 720 (such as a layer or layers comprising, for example,chromium, chromium/rhodium, aluminum, silver, aluminum alloy, silveralloy, an ITO/silver/ITO stack, an ITO/aluminum/ITO stack or the like,such as ITO-silver-ITO stacks or layers, or display on demand stacks orlayers or infrared transmitting stacks or layers of the types describedin PCT application No. PCT/US03/29776, filed Sep. 19, 2003 by DonnellyCorporation et al. for MIRROR REFLECTIVE ELEMENT ASSEMBLY, publishedApr. 1, 2004 as International Publication No. WO 2004/026633 A2, whichis hereby incorporated herein by reference) on its front or thirdsurface 714 a, and a perimeter black seal 717 generally around theperimeter edges of the substrate. As can be seen in FIG. 25B, anelectrical connection area 727 may be defined at a region of the rearsubstrate 714, such as at a corner of the substrate, where the perimeterseal 717 is positioned inward of the outer edge of the substrate. Therear substrate 714 is formed to be substantially identical in shape tothe front substrate 712, except at the electrical connection area 727,where the rear substrate may be cut back or reduced along a cut-away orcut back edge 714 c. The conductive bridge 723 is positioned at aportion of the electrical connection area 727 to provide electricalconnection to the metallic reflective coating or layer 720 viaelectrical connector 724 at front substrate 712.

When the substrates 712, 714 are placed together to form theelectro-optic or electrochromic mirror cell or reflective elementassembly (with the electro-optic or electrochromic medium disposed orsandwiched therebetween), the electrical connection area 727 of rearsubstrate 714 generally aligns with a portion of the electricalconnection area 725 of front substrate 712. The conductive bridge 723bridges or spans the gap or spacing between the electrical connectionareas 725 a and 727 to connect the electrical contact or connector 724and electrical connection area 725 a to the metallic conductivereflective layer 720 of rear substrate 714.

The cut-away edge 714 c of rear substrate 714 provides for exposure ofthe electrical connectors or contacts 722, 724 along the outer edge 712c of the electrical connection area 725 of front substrate 712. Theelectrical contacts for providing electrical power to the conductive orsemi-conductive layers at both substrates are made at only one of thesubstrates. The other edges of the substrates 712, 714 are generallyflush or aligned to form a flush reflective element assembly for anexterior rearview mirror assembly. The reflective element assembly maythus be implemented in a mirror assembly having a minimal bezel or abezelless mirror assembly to enhance the appearance of the mirrorassembly.

Referring now to FIGS. 26 and 27, an electro-optic or electrochromicmirror cell or reflective element assembly 810 includes a frontsubstrate 812 and a rear substrate 814 and an electro-optic orelectrochromic medium 816 sandwiched between the semi-conductive orconductive layers 818, 820 on the surfaces 812 a, 814 a of thesubstrates 812, 814, respectively. A dimension of the front substrate,such as a height dimension, is greater than that of the rear substrate,such that the upper and lower perimeter regions or edge portions 812 b,812 c of front substrate 812 extend beyond the upper and lower perimeterregions or edge portions 814 f, 814 g of rear substrate 814 and defineoverhang regions 812 f, 812 g. As shown in FIG. 26, the conductive layer820 of rear substrate 814 does not extend fully over third surface 814 aat the perimeter region 814 g of substrate 814. Third surface 814 a maybe masked during the coating process, such that a non-conductive glasssurface 814 e is provided generally along the perimeter region 814 g ofsurface 814 a.

Reflective element assembly 810 includes electrical connectors 824, 822at a rear surface 814 b of rear substrate 814 and at least partiallyalong the upper edge 814 c and lower edge 814 d of rear substrate 814,respectively. The connectors may be disposed partially at the rearsurface 814 b of rear substrate 814 and may extend along and overlap theedges 814 c, 814 d of rear substrate 814. The electrical or metallicconnectors 824, 822 are in electrical connection with the respectiveconductive layers 820, 818 and may be connected to an electrical powersource or circuitry or the like to provide electrical power to thesemi-conductive coatings 818, 820 to darken or color the electrochromicmedium 816. The front substrate 812 includes a deletion line 821 alongthe upper portion 812 b of the substrate and along the semi-conductivecoating or layer 818 on the rear surface 812 a of substrate 812. Thedeletion line 821 defines an electrically isolated area or region 821 aalong a perimeter region of substrate 812, such as along the upperportion of the substrate 812.

As can be seen with reference to FIG. 27, the reflective elementassembly 810 includes a non-conductive perimeter seal 817 around theelectrochromic medium 816, as is known in the art. The seal 817 overlapsand at least partially or substantially fills or encompasses thedeletion line 821 along one side of the reflective element assembly andat least partially or substantially fills or covers or encompasses themasked surface 814 e along the other side of the reflective elementassembly. A conductive material or adhesive or bridge or the like 823 ais disposed or applied along the upper region of the front substrate andoutside of the seal 817, while a conductive material or adhesive orbridge or the like 823 b is disposed or applied along the lower regionof the front substrate and outside of the seal 817. Accordingly, whenpower is applied to connector 822, the connector provides or deliverspower to or energizes the semi-conductive layer 818 on front substrate812 via the conductive bridge 823 b (whereby the conductive bridge mayfunction as an electrical raceway along the edge of the reflectiveelement assembly). The non-conductive seal 817 and non-conductivesurface 814 e of rear substrate 814 function to electrically isolate orinsulate connector 822 and conductive bridge 823 b from conductivecoating or layer 820 of rear substrate 814. When power is applied toconnector 824, the connector provides or delivers power to theconductive layer 820 on rear substrate 814 via contact of the connector824 along the edge of the conductive coating 820 and via the conductivebridge 823 a along the edge or perimeter region of the reflectiveelement assembly. The conductive bridge 823 a and raceway portion 821 amay function as an electrical raceway along an edge portion or perimeterregion of the conductive layer or coating 820 of rear substrate 814. Theconductive bridge 823 a does not power the semi-conductive layer 818 onfront substrate 812 because the conductive bridge 823 a is at theelectrically isolated area 821 a along the upper portion or perimeterregion of the front substrate.

Optionally, and as shown in FIG. 28, an electro-optic or electrochromicmirror cell or reflective element assembly 810′ may include metallicconnectors 822′, 824′ that extend across the gap between the substrates812, 814 and contact the semi-conductive layer 818 on the rear surface812 a of the front substrate 812. The conductive bridge 823 functions tocommunicate the power from connector 824′ to the conductive layer 820 onthe front surface 814 a of rear substrate 814. The deletion line 821defines the electrically isolated area 821 a along the front substratewhere the connector 824′ connects to or contacts the semi-conductivelayer 818 of the front substrate 812 at the overhang region 812 f offront substrate 812. The connector 822′ contacts the surface portion ofthe semi-conductive layer 818 (which substantially covers the rearsurface of the front substrate 812) along the other border or perimeterregion or overhang region 812 g of the front substrate. Thenon-conductive glass surface 814 e and non-conductive perimeter seal 817function to electrically isolate or insulate the connector 822′ fromconductive coating 820 of rear substrate 814. The mirror cell orreflective element assembly 810′ is otherwise substantially similar tothe reflective element assemblies discussed above, such that a detaileddiscussion of the reflective element assembly will not be repeatedherein.

Optionally, and as shown in FIG. 29, a reflective element assembly 810″is substantially similar to the reflective element assembly 810′,discussed above, but includes conductive pins or foil strips 822″, 824″.The foil strips 822″, 824″ are disposed between a heater pad or backingplate 811 and the semi-conductive layer 818 at the rear surface 812 a ofthe front substrate 812. The strips 822″, 824″ may include one or morepins or extensions 822 a″, 824 a″ extending rearwardly through thebacking plate 811 for connection to an appropriate power source, controlor circuitry or the like. The conductive bridge 823 functions tocommunicate the power from strip 824″ to the conductive layer 820 on thefront surface 814 a of rear substrate 814. The deletion line 821 definesthe electrically isolated area 821 a along the front substrate where thestrip 824″ connects to or contacts the semi-conductive layer 818 of thefront substrate 812. The strip 822″ contacts the surface portion of thesemi-conductive layer 818 along the other border or perimeter region ofthe front substrate and may function as an electrical raceway along theborder region of the semi-conductive layer 818. The mirror cell orreflective element assembly 810″ is otherwise substantially similar tothe reflective element assemblies discussed above, such that a detaileddiscussion of the reflective element assembly will not be repeatedherein.

Optionally, and with reference to FIG. 30, a reflective element assembly810′″ includes metallic connectors or strips or foil 822′″, 824′″ thatare inserted partially between the substrates 812, 814. The strip orfoil 822′″ extends across the gap between the substrates 812, 814 andcontacts the semi-conductive layer 818 on the rear surface 812 a of thefront substrate 812 and generally at the overhang region 812 g. Thestrip or foil 824′″ contacts and connects to the conductive layer 820 onthe front surface 814 a of rear substrate 814. The deletion line 821defines the electrically isolated area or raceway portion 821 a alongthe front substrate where the strip or foil 824′″ is generallypositioned to isolate that portion of the front substrate to avoidshorting of the cell or reflective element assembly due to anycontacting of the strip or foil 824′″ to the surface portion of thesemi-conductive layer 818 of the front substrate 812. The mirror cell orreflective element assembly 810′″ is otherwise substantially similar tothe reflective element assemblies discussed above, such that a detaileddiscussion of the reflective element assembly will not be repeatedherein. As can be seen in FIG. 31, the connectors or strips or foils822′″, 824′″ may be insulated on their sides 822 a′″, 824 a′″ oppositeto their electrically contacting side, such that the deletion line isnot necessary.

Optionally, and with reference to FIG. 32, an electro-optic orelectrochromic cell or reflective element assembly 910 includes a frontsubstrate 912 and a rear substrate 914 with an electro-optic orelectrochromic medium 916 sandwiched between a semi-conductive layer orcoating (such as ITO or the like) 918 on the rear surface 912 a of thefront substrate 912 and a conductive layer or coating 920 (such assilver, silver alloy, or the like) on the front surface 914 a of therear substrate 914. A perimeter seal 917 is disposed around theelectrochromic medium 916. As can be seen in FIG. 32, the conductivelayer 920 is applied or coated or oversprayed at least partially ontothe edges 914 b, 914 c of the rear substrate 914. The conductive layer920 on the rear substrate 914 includes a deletion line 921 to define anelectrically isolated area or raceway portion 921 a along a perimeter orborder region or portion of the rear substrate 914. A conductivematerial or bridge 923 (such as a conductive epoxy, frit, paste or thelike) is disposed along the perimeter or border region and between theelectrically isolated area 921 a and the semi-conductive layer 918 offront substrate 912.

An electrical connector 922 is disposed at the rear substrate, such aspartially along the rear surface 914 d of rear substrate 914, andoverlaps at least a portion 920 a of the conductive layer 920 on theedge 914 b of rear substrate 914, thereby providing an electricalconnection from the rear of the reflective element assembly 910 to theelectrically isolated area 921 a of the conductive layer 920. Theconnector 922 thus provides an electrical connection to thesemi-conductive layer 918 on the rear surface 912 a of the frontsubstrate 912 via the conductive bridge 923 extending along and betweenthe isolated area 921 a and the semi-conductive layer 918 at theperimeter or border regions of the front and rear substrates. Theisolated area 921 a and the conductive bridge 923 provide an electricalraceway along a perimeter or border portion of the semi-conductive layer918 to enhance the performance of the reflective element assembly 910.

A second electrical connector 924 is disposed partially along the rearsurface 914 d of the rear substrate 914 and overlaps at least a portion920 b of the conductive layer 920 at the edge 914 c of rear substrate914, thereby providing an electrical connection from the rear of thereflective element assembly 910 to the conductive layer 920 along thefront surface 914 a of rear substrate 914.

Referring now to FIGS. 33A-C, an electro-optic or electrochromic cell orreflective element assembly 1010 includes a front substrate 1012 and arear substrate 1014 with an electro-optic or electrochromic medium 1016sandwiched between a semi-conductive layer or coating (such as ITO orthe like) 1018 on the rear surface 1012 a of the front substrate 1012and a conductive layer or coating (such as silver, silver alloy or thelike) 1020 on the front surface 1014 a of the rear substrate 1014. Aperimeter seal 1017 is disposed around the electrochromic medium 1016.The semi-conductive layer 1018 on the front substrate 1012 includes adeletion line 1019 to define an electrically isolated area or racewayportion 1019 a along a perimeter or border region or portion 1012 b ofthe front substrate 1012, while the conductive layer 1020 on the rearsubstrate 1014 includes a deletion line 1021 to define an electricallyisolated area or raceway portion 1021 a along a perimeter or borderregion or portion 1014 b of the rear substrate 1014. A conductivematerial or bridge 1023 a (such as a conductive epoxy, film, frit, pasteor the like) is disposed along the perimeter or border region 1012 b andbetween the electrically isolated area 1019 a and the conductive layer1020 of rear substrate 1014, while a second conductive material orbridge 1023 b (such as a conductive epoxy, film, frit, paste or thelike) is disposed along the opposite perimeter or border region 1014 band between the electrically isolated area 1021 a and thesemi-conductive layer 1018 of front substrate 1012.

As can be seen in FIGS. 33B and 33C, the rear substrate 1014 includes apair of notches 1025 a, 1025 b to provide for electrical contact to therespective conductive bridges 1023 a, 1023 b. As best shown in FIG. 33C,an electrical connector or contact (not shown) may engage or contact theconductive bridge 1023 a at the notch or cut away 1025 a, whereby theconductive bridge 1023 a may function as an electrical raceway along theborder region 1014 c of rear substrate 1014, while the electricallyisolated area 1019 a and deletion line 1019 of border region 1012 b offront substrate 1012 substantially precludes electrical power fromreaching the semi-conductive layer 1018 along the rear surface 1012 a offront substrate 1012. Likewise, another electrical connector or contactmay engage or contact the conductive bridge 1023 b at the notch or cutaway 1025 b, whereby the conductive bridge 1023 b may function as anelectrical raceway along the border region 1012 c of front substrate1012, while the electrically isolated area 1021 a and deletion line 1021of border region 1014 b of rear substrate 1014 substantially precludeselectrical power from reaching the conductive layer 1020 along the frontsurface 1014 a of rear substrate 1014.

Referring now to FIG. 34, an electro-optic or electrochromic cell orreflective element assembly 1110 includes a front substrate 1112 and arear substrate 1114 with an electro-optic or electrochromic medium 1116sandwiched between a semi-conductive layer or coating (such as ITO orthe like) 1118 on the rear surface 1112 a of the front substrate 1112and a conductive layer or coating (such as silver, silver alloy, or thelike) 1120 on the front surface 1114 a of the rear substrate 1114. Aperimeter seal 1117 is disposed around the electrochromic medium 1116.The front substrate 1112 includes an opaquifying or darkening orblackening or concealing or hiding non-conductive border coating 1119disposed around the perimeter regions or border of the rear surface 1112a. The border coating 1119 may comprise a decorative and/or colormatching coating, and may be colored to match the body color, the colorof the mirror case or the color of the electrochromic medium in itsnight state, or any other desired color. The transparent semi-conductivecoating or layer 1118 is disposed on the rear surface 1112 a of frontsubstrate 1112 and may at least partially overlap the non-conductiveborder coating 1119, at least along one border region 1112 b of thefront substrate 1112, such as shown in FIG. 34.

Reflective element assembly 1110 includes an electrical connector 1122that may be disposed at a perimeter or border region 1110 a of thereflective element assembly for providing or delivering electrical powerto the semi-conductive layer 1118 of front substrate 1112 via aconductive bridge or adhesive 1123 a. As can be seen in FIG. 34, theconnector 1122 is formed to overlay the rear surface 1114 b of rearsubstrate 1114 and extend along an edge 1114 c of the rear substrate andcontact the conductive bridge 1123 a disposed between the connector 1122and the semi-conductive layer 1118 and outside of the perimeter seal1117 at the overhang region 1112 g. The conductive layer 1120 may notextend fully across the front surface 1114 a of rear substrate 1114 atthe connector 1122, so that a non-conductive glass surface 1114 e isdefined along the perimeter edge portion or region 1114 c of rearsubstrate, whereby a gap is defined between the connector 1122 andconductive layer 1120. The non-conductive glass surface 1114 e or gapand the non-conductive perimeter seal 1117 function to electricallyisolate or insulate the connector 1122 from conductive coating 1120 ofrear substrate 1114 to preclude shorting of the electrochromic cell orreflective element assembly.

Likewise, a second electrical connector 1124 may be disposed on anotherperimeter region 1110 b of the reflective element and may be formed tooverlay the rear surface 1114 b of rear substrate 1114 and extend alongan edge 1114 d of the rear substrate and contact the conductive bridge1123 b disposed between the connector 1124 and the conductive layer 1120and outside of the perimeter seal 1117. The conductive layer or coating1118 of front substrate 1112 may not extend fully across the surface1112 a of front substrate 1112 so as to define a non-conductive surfaceor area of border coating 1119 at conductive bridge 1123 b and generallyat the overhang region 1112 f. The second surface 1112 a of frontsubstrate 1112 and the non-conductive border coating 1119 andnon-conductive seal 1117 function to electrically isolate or insulatethe connector 1124 and conductive adhesive 1123 b from the conductivecoating 1118 of front substrate 1112. The second connector 1124 mayprovide electrical power to the metal reflector coating or conductivelayer 1120 on the rear substrate 1114, with the conductive adhesive 1123b acting as a raceway along a perimeter or border region of the frontsurface of the rear substrate 1114. The connectors 1122, 1124 may beconnected to an appropriate power source, control, circuitry or the likefor controlling the electrochromic cell or reflective element assembly.

Optionally, and as shown in FIG. 35, an opaquifying non-conductiveborder coating or layer 1119′ may be disposed along the front surface1112 c of front substrate 1112 to provide a decorative border coatingalong the perimeter or border regions of the front surface 1112 c offront substrate 1112. The transparent semi-conductive coating or layer1118′ thus may be disposed on the rear surface 1112 a of front substrate1112 in a generally uniform thickness and may coat the border region1112 b, but may not extend to the border region 1112 d, thereby defininga non-conductive area or electrically isolated area or non-conductiveglass surface 1112 e at the border region 1112 d. The non-conductiveglass surface 1112 e and non-conductive seal 1117 function toelectrically isolate or insulate the conductive coating 1118 of frontsubstrate 1112 from connector 1124 and conductive adhesive 1123 bgenerally at the overhang region 1112 f. Likewise, and as describedabove, the conductive coating 1120 may not extend to the edge 1114 c ofrear substrate 1114 to define a non-conductive glass surface 1114 e atand adjacent to connector 1122, so that connector 1122 is electricallyisolated and insulated from conductive coating 1120 by non-conductivesurface 1114 e and non-conductive seal 1117. Optionally, and as shown inFIG. 36, an opaquifying border 1119″ may be embedded in the borderregions 1112 b′, 1112 d′ of the front substrate 1112′, such as via aradiation induced coloration in the glass of the substrate or via othermeans or processes.

Referring now to FIG. 37, an electro-optic or electrochromic cell orreflective element assembly 1210 includes a front substrate 1212 and arear substrate 1214 with an electro-optic or electrochromic medium 1216sandwiched between a semi-conductive layer or coating (such as ITO orthe like) 1218 on the rear surface 1212 a of the front substrate 1212and a conductive layer or coating (such as silver, silver alloy, or thelike) 1220 on the front surface 1214 a of the rear substrate 1214. Theconductive coating 1220 of rear substrate 1214 does not extend fully tothe edge 1214 c of substrate 1214, so that a non-conductive glasssurface or area or region 1214 e is defined on surface 1214 a along theperimeter portion at edge 1214 c. A non-conductive perimeter seal 1217is disposed around the electrochromic medium 1216 and may at leastpartially or substantially fill or cover or encompass the non-conductiveglass surface 1214 e. The non-conductive glass surface 1214 e andnon-conductive seal 1217 thus function to electrically isolate orinsulate the conductive coating 1220 from the connector 1222 andconductive adhesive 1223 a.

The front substrate 1212 includes an opaquifying or darkening orblackening or concealing or hiding non-conductive border coating 1219 adisposed over the semi-conductive layer 1218 and around or along aperimeter region or border 1212 b of the rear surface 1212 a of thefront substrate 1212, and an opaquifying conductive border coating 1219b disposed over the semi-conductive layer 1218 and around or along aperimeter region or border 1212 c of the rear surface 1212 a of thefront substrate 1212. The transparent semi-conductive coating or layer1218 may include a deletion line 1221 to define an electrically isolatedarea or region 1221 a, with the non-conductive border coating 1219 adisposed along the semi-conductive layer 1218 and over the deletion line1221. The non-conductive border coating 1219 a may at least partially orsubstantially fill in or encompass deletion line 1221. Thenon-conductive border coating 1219 a and deletion line 1221 thusfunction to electrically isolate or insulate the conductive coating 1218from electrical connector 1224.

In the illustrated embodiment, the reflective element assembly 1210includes an encapsulant 1225 which substantially surrounds the rear andside edges of the reflective element assembly and may cover or overlay aheater pad or the like 1227 at the rear surface 1214 b of the rearsubstrate 1214. The encapsulant 1225 extends along the edges 1214 c,1214 d of rear substrate 1214, and further at least partially along theperimeter edges 1212 d, 1212 e of front substrate 1212. A metalconnector 1222 may be provided through the encapsulant 1225 to power orenergize the semi-conductive layer 1218 on rear surface 1212 a of frontsubstrate 1212 via a conductive bridge or epoxy or adhesive 1223 adisposed at least partially around the connector 1222 and between theconnector 1222 and the opaquifying conductive border coating 1219 b. Ascan be seen in FIG. 37, the connector 1222 may be disposed generallywithin the conductive bridge 1223 a and the non-conductive glass surface1214 e and non-conductive seal 1217 may separate or isolate theconnector 1222 and conductive bridge 1223 a from the conductive layer orcoating 1220 of rear substrate 1214, in order to avoid contact orelectrical communication between the connector 1222 and the conductivelayer 1220 on front surface 1214 a of rear substrate 1214.

Likewise, the metal connector 1224 may be provided through theencapsulant 1225 to power or energize the conductive layer 1220 on frontsurface 1214 a of rear substrate 1214 via a conductive bridge or epoxyor adhesive 1223 b disposed at least partially around the connector 1224and between the connector 1224 and the opaquifying conductive bordercoating 1219 a, and further between the opaquifying conductive bordercoating 1219 a and the conductive layer 1220. The non-conductive bordercoating 1219 a and deletion line 1221 thus serve to electrically isolatethe connector 1224 and conductive bridge 1223 b from conductive layer orcoating 1218 of front substrate 1212.

Optionally, and with reference to FIG. 38, the conductive bridge oradhesive 1223 b′ may be disposed at the overhang regions 1212 f, 1212 gof the front substrate 1212, with the perimeter seal 1217′ disposedgenerally flush with the edges 1214 c, 1214 d of the rear substrate1214. As can be seen in FIG. 38, the connectors 1222, 1224 may bepositioned generally within the respective conductive bridges 1223 a,1223 b′, whereby the electrical contact to the conductive coating 1219 b(and the semi-conductive layer 1218′) and to the conductive layer 1220is through the respective conductive bridges 1223 a′, 1223 b′. Theconductive metallic reflector layer 1220 on front surface 1214 a of rearsubstrate 1214 may not be applied at the outer perimeter region of thefront surface 1214 a to provide a non-conductive glass surface or regionor area 1214 e at or near or adjacent to the connector 1222 andconductive bridge 1223 a′ to electrically isolate or insulate connector1222 and conductive bridge 1223 a′ from conductive layer 1220 of rearsubstrate 1214.

The conductive bridge 1223 b′ may contact the conductive layer 1220along an edge portion 1220 a of the conductive layer. Optionally, insuch an embodiment, the edge portion 1220 a of the metallic reflector orconductive layer 1220 may wrap at least partially around the edgedimension 1214 d of the rear substrate 1214 to extend partially alongthe edge 1214 d, and the encapsulant 1225 may provide a cavity 1225 apartially along the edge 1214 d for receiving the conductive bridge orepoxy or adhesive or paste or frit or the like 1223 b′ to providecontact to the conductive layer 1220 along the wrapped edge portion 1220a of the conductive layer 1220 to enhance the electrical contact andconductivity from the connector 1224 to the conductive layer 1220. Thereflective element assembly 1210′ thus may provide an enlargedelectro-optic or electrochromic region of the reflective elementassembly by reducing the conductive bridge region for the conductiveadhesive or bridge 1223 b′.

Therefore, the present invention provides an electro-optic orelectrochromic reflective element assembly that provides electricalcontact to electrical raceways or conductive layers or coatings alongregions or border or perimeter regions of the assembly that have arestricted overhang. The electrical connections may be made at overhangregions of the front substrate where the perimeter regions of the frontsubstrate extend beyond the corresponding perimeter regions of the rearsubstrate, such that the electrical connectors are not viewable throughthe front surface of the front substrate. The present invention thus mayprovide a reduced or minimal bezel or no bezel assembly and may provideenhanced performance of the electrochromic mirror assembly. Theconductive epoxy or adhesive or bridge may provide an electrical racewayalong a perimeter or border portion of the semi-conductive and/orconductive layers of the substrates to provide rapid electrical flowalong the layers or coatings to further provide rapid and substantiallyuniform darkening or coloring of the electrochromic medium. Theconnectors and bridges of the present invention facilitate such enhancedperformance at a restricted overhang region and thus provide for aminimal bezel or no bezel around the perimeter of the reflective elementassembly. The electrical connectors are electrically isolated orinsulated from the other conductive layer or coating via anon-conductive surface and non-conductive seal being positioned betweenthe connector and the respective other conductive layer.

In the embodiments described above, it is envisioned that thenon-conductive glass surfaces (where applicable) may be formed bymasking the surface of the substrate during coating or deposition of theconductive layer or coating, or may be formed by etching (such as laseretching, chemical etching, mechanical etching or the like) or otherwiseremoving the conductive layer or coating at the desired area or region,such as via a high voltage discharge to remove or burn the coating offof the desired area or region. The masked portion or etched portion ornon-conductive portion may be generally at the outer perimeter or edgeof the coating, and may have a width of approximately 0.05 mm, orapproximately 0.1 mm, or up to approximately 1 mm. The masked portion ornon-conductive surface may be partially or substantially filled orencompassed by the non-conductive seal or by other non-conductive layersor the like disposed at the surface of the substrate. Likewise, thedeletion lines (where applicable) may be formed on and through therespective conductive or semi-conductive layer to define electricallyisolated areas or regions of the layers. The deletion lines may beformed via any known manner, such as via chemical etching, mechanicallyetching or, and preferably, laser etching of the layers. The size orwidth of the deletion line is selected to be sufficient to create anelectrical break so there is no electrical conductivity between thelayer and the electrically isolated region of the layer. Typically, thedeletion lines may be formed to be approximately 0.01 mm toapproximately 0.5 mm or thereabouts.

Also, the perimeter seal that generally surrounds the electrochromicmedium and spaces the front and rear substrates may have a width ofpreferably approximately 0.5 mm to approximately 3 mm, more preferablyapproximately 1 mm to approximately 2 mm, and most preferablyapproximately 1.25 mm to approximately 1.75 mm. The overhang that isdefined at the edges of the substrates (where, for example, the rearsubstrate may be smaller than the front substrate) may be preferablyapproximately 0.1 mm to approximately 2 mm, more preferablyapproximately 0.25 mm to approximately 1.5 mm, and most preferablyapproximately 0.75 mm to approximately 1.25 mm.

In addition to other materials to be used as conductive busbars (such assilver frit, paste, conductive inks, and/or the like), optionally,ultrasonic soldering techniques may be used to apply a busbar whichconsists of solder (typically, standard soldering technique may notprovide good adhesion/flow between the solder and a glass substrate).The solder can be used to provide a busbar for an semi-conductivecoating (such as ITO or the like) or for a metallic coating. Forexample, an ultrasonic soldering system made by Asahi Glass company ofJapan (e.g., Model: Sunbonder USM-3) may be used for applying thisspecial solder. The solders that may be used include, for example,ultrasonic solders 143 and 297, available from Asahi Glass company.However, other materials may be implemented, such as conductive inks,pastes, frits, and the like, without affecting the scope of the presentinvention.

Optionally, and with reference to FIG. 39, the rear or smaller substrate1314 of an electro-optic or electrochromic cell or reflective elementassembly 1310 may be formed to have a tab out portion or protrusion 1314a along one edge. The electro-optic or electrochromic medium may then beinjected through an opening or gap in the perimeter seal 1317 (thatspaces the front substrate 1312 from the rear substrate 1314) thatgenerally corresponds with the outward protrusion 1314 a of the rearsubstrate 1314. A plug is applied or inserted into the gap to seal theelectrochromic medium within the perimeter seal and the substrates afterthe electrochromic medium is injected. Typically, such plugs may bedifficult to insert in non-flush edges of mirror cells because they maybe visible if they are inserted too far into the gaps in the seals. Thetab out portion 1314 a of the rear substrate 1314 provides an edgeportion that is generally flush with the front substrate to provide alarger area for the plug to be positioned at without having the pluginsert into the area where it may be visible to a user of the mirrorassembly. Optionally, an opaquifying or hiding or darkening layer of thereflective element assembly (if applicable) may be expanded in that areato cover or conceal or hide the plug and tab out portion.

Optionally, the electro-optic or electrochromic cell or reflectiveelement assembly of the present invention and the electrical connectorsthereon or therearound may be coated with a protective coating to limitor reduce corrosion that may occur on the electrical connectors overtime. The coating may comprise a parylene coating or parylene C coatingor the like to enhance corrosion resistance (or may comprise other knownparylene coatings, such as a parylene N coating, a parylene D coating ora parylene HT coating or the like). Such a parylene coating may beformed in a plasma chamber or vacuum applied and is highly penetratingor permeating so that the parylene coating may penetrate and surroundthe metal electrical clips or pins or connectors and seal them to limitcorrosion of the electrical components. The parylene coating maycomprise a thin coating (such as, for example, approximately 2.5 μm toabout 12.5 μm) which coats and permeates anything placed in the chamberand not otherwise covered or masked. The parylene coating may comprise avacuum applied polymer that is either in a gaseous or solid state, andmay possess substantial dielectric and barrier properties per unitthickness. Such parylene coatings are known and are typically used inposition sensor applications, intake manifold pressure sensorapplications, gas sensor applications and valve cover gasketapplications for vehicles.

For example, an electrical clip or connector may be in contact with thesemi-conductive or conductive layer and may be susceptible or vulnerableto corrosion at the point where the two come in contact (particularly ina high moisture or salt environment and particularly for exteriorrearview mirror assemblies). A parylene coating may be applied tosubstantially seal the connector at the semi-conductive or conductivelayer to resist such corrosion. The electrochromic cell or reflectiveelement assembly (with electrical contacts or connectors attachedthereto) may be placed in a chamber and the parylene coating may beapplied, such as via a vacuum vapor deposition process or the like.Optionally, two or more cells may be stacked in a stepped or offsetmanner, such that the edges of each cell are exposed to the parylenecoating, while the above and below cell act as a mask over the rest ofthe cell. The parylene coating thus may only be applied to the offsetarea. The cells of the stack of cells thus may act as a self maskingelement for the other cells of the stack. Such a self masking approachwith multiple cells may be particularly useful for parylene coatingsbecause of the amount of time that it typically may take to coat an itemwith such parylene coatings.

The parylene raw material (di-para-xylylene dimer) is a crystallinepowder and may be vaporized at approximately 150 degrees C. and thenmolecularly cleaved or pyrolyzed at approximately 680 degrees C. Thisforms the para-xylylene, which may be introduced generally at roomtemperature into a vacuum deposition chamber as a monomeric gas thatpolymerizes substantially evenly on the substrates. The coating thengrows as a conformal film on all of the exposed surfaces, edges, etc. ofthe substrates or cells.

Testing has shown that a known conventional corrosion protection coatingor seal may allow corrosion of the electrical contacts and failure ofthe mirror after about 12 weeks in a salt spray test chamber (such as atest chamber conducting tests in accordance with ASTM B-117, which ishereby incorporated herein by reference), while a substantiallyidentical or similar mirror coated with a parylene C coating may besubstantially unchanged, with the electrical contacts remaining at leastsubstantially uncorroded, after about 22 weeks in the same salt spraytest chamber and undergoing the same salt spray test. The parylenecoating thus provides substantial enhancement of corrosion resistanceand the mirror reflective element life cycle over known mirror corrosionprotection means.

Optionally, the mirror assemblies or reflective element assemblies orcells of the present invention may include one or more displays fordisplaying information to the driver or occupant of the vehicle.Optionally, the conductive or semi-conductive layers of the reflectiveelement assembly may have a metallic layer which may be absent orremoved at portions, such as to create a local window for placementtherebehind of a light emitting display, such as a compass display orPSIR display or other informational display or the like, such as adisplay of the type disclosed in commonly assigned U.S. Pat. Nos.6,222,460 and 6,326,900, which are hereby incorporated herein byreference in their entireties, but while maintaining at least theunderlying semi-conducting layer at the local window region so thatelectrical connection through the electrochromic medium at that localregion is sustained.

Optionally, the reflective element assembly of the present invention mayinclude other display systems or elements (not shown) which are operableto provide, emit or display information or light through the reflectiveelement assembly. The light is emitted through the reflective elementassembly at a display area, such that the display information or lightis viewable by a driver of the vehicle. The second or rear substrate andthe respective semi-conductive layers of the reflective element assemblyor cell then comprise a transflective one way mirror, such as disclosedin commonly assigned U.S. pat. application, Ser. No. 10/054,633, filedJan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM, which ishereby incorporated herein by reference. Preferably, the reflectiveelement assembly (behind which the display is disposed so that theinformation displayed is visible by viewing through the reflectiveelement assembly) of the mirror assembly comprises a transflectivemirror reflector or reflective element assembly such that the mirrorreflective element assembly is significantly transmitting to visiblelight incident from its rear (i.e., the portion furthest from the driverin the vehicle), while simultaneously, the mirror reflective elementassembly is substantially reflective to visible light incident from itsfront (i.e. the position closest to the driver when the mirror assemblyis mounted in the vehicle, such as is disclosed in U.S. pat.application, Ser. No. 09/793,002, filed Feb. 26, 2001 by Schofield etal. for VIDEO MIRROR SYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S.Pat. No. 6,690,268; and/or in U.S. Pat. Nos. 5,668,663 and 5,724,187,the entire disclosures of which are hereby incorporated by referenceherein.

The display system preferably comprises a display-on-demand type ofdisplay and includes a display element or light emitting device (alsonot shown) positioned at the back or fourth surface of the rearsubstrate. The display element is operable to emit light, such as in theform of indicia, alphanumeric characters, images, or the like, inresponse to a control or input. The display element may be a vacuumfluorescent (VF) display, a light emitting diode (LED), an organic lightemitting diode (OLED), a gas discharge display, a plasma display, acathode ray tube, a backlit active matrix LCD screen, anelectroluminescent display, a field emission display or the like,without affecting the scope of the present invention. The particulardisplay element may be selected to provide a desired color to thedisplay. For example, a VF display may be selected to provide ablue-green color or other colors to the information displayed (dependingon the phosphor selected for the display), while a light emitting diodemay be selected to provide other colors, such as reds, ambers, or othercolors.

Preferably, the display is a display-on-demand type of display, such asof the types disclosed in commonly assigned U.S. Pat. Nos. 5,668,663 and5,724,187, and/or in U.S. pat. application, Ser. No. 10/054,633, filedJan. 22, 2002 by Lynam et al. for VEHICULAR LIGHTING SYSTEM; and/or Ser.No. 09/792,002, filed Feb. 26, 2001 by Schofield et al. for VIDEO MIRRORSYSTEMS INCORPORATING AN ACCESSORY MODULE, now U.S. Pat. No. 6,690,268,which are all hereby incorporated herein by reference. With such adisplay, it is not only desirable to adjust the display brightnessaccording to ambient lighting conditions, but it is also desirable toadjust the display brightness such that a sufficient contrast ratio ismaintained against the variable background brightness of the reflectedscene. Also, it may be desirable to compensate for changes intransmission of the electrochromic device affected to control rearwardglare sources, in order that the display brightness appears to bemaintained at a generally constant level.

In certain conditions, the ambient light intensity within the cabin ofthe vehicle may be sufficiently high so that reflected light from themirror reflective element and, in particular, from the display region,tends to “wash-out” the display. It is envisioned that this glare may bereduced by taking advantage of the electrochromic function of the mirrorassembly. More particularly, the electro-optic or electrochromic mediumof the electro-optic or electrochromic reflective element assembly maybe colored or darkened in the area of the display by constructing alocally addressable region across the display. This may be achieved bycreating a deletion line in the second surface semi-conductive layer atthe second surface of the first or front substrate and/or in the thirdsurface semi-conductive layer of the rear substrate, hence breakingelectrical continuity from the rest of the electrochromic cell. Anambient light sensor (not shown) may be used to detect the criticalambient light levels at which “wash-out” is a problem. The addressableregion may then be separately colored or darkened to the appropriatelevel to reduce the glare from the display area in response to theambient light sensor. Although such a glare problem could be solved bycoloring the entire mirror, by localizing the region of coloration toonly the display area, the electrochromic mirror assembly of the presentinvention allows the rest of the mirror reflective area, which does notincorporate the display, to retain full reflectivity while the displayarea is colored or darkened (such as may be useful when driving by day).

In order to maintain easy viewing of the display, it is desirable toadjust the display intensity in response to ambient light levels (inorder to avoid washout during daytime driving conditions and glareduring nighttime driving conditions) and in response to the degree oftransmissivity of the electrochromic reflective element. For example, inlow lighting conditions, such as during the nighttime, the intensity ofthe display may be dimmed to avoid glare, while in higher lightingconditions, such as during the daytime, the intensity of the display maybe increased to provide sufficient visibility of the display to thedriver of the vehicle. The mirror assembly may include light sensors forsensing the ambient light in the cabin of the vehicle or at the mirrorassembly and may include a control which is operable to automaticallyadjust the display intensity and/or the transmissivity of theelectrochromic medium in response to the ambient light sensors.

Further, automatic dimming circuitry used in electro-optic orelectrochromic mirror assemblies utilizing the reflective elementassemblies of the present invention may utilize one or more (typicallytwo) photo sensors to detect glaring and/or ambient lighting. Forexample, a silicon photo sensor, such as a TSL235R Light-to-Frequencyconverter (available from Texas Advanced Optoelectronic Solutions Inc.of Plano, Tex.), can be used as such photo sensors. Suchlight-to-frequency converters comprise the combination of a siliconphotodiode and a current-to-frequency converter on a single monolithicCMOS integrated circuit.

The reflective element assembly or assemblies of the present inventionmay also include or house a plurality of electrical or electronicdevices, such as antennas, including global positioning system (GPS) orcellular phone antennas, such as disclosed in U.S. Pat. No. 5,971,552, acommunication module, such as disclosed in U.S. Pat. No. 5,798,688,displays, such as shown in U.S. Pat. Nos. 5,530,240 and 6,329,925, blindspot detection systems, such as disclosed in U.S. Pat. No. 5,929,786 or5,786,772, transmitters and/or receivers, such as garage door openers, adigital network, such as described in U.S. Pat. No. 5,798,575, ahigh/low head lamp controller, such as disclosed in U.S. Pat. No.5,715,093, a memory mirror system, such as disclosed in U.S. Pat. No.5,796,176, a hands-free phone attachment, a video device for internalcabin surveillance and/or video telephone function, such as disclosed inU.S. Pat. Nos. 5,760,962 and 5,877,897, a remote keyless entry receiver,map lights, such as disclosed in U.S. Pat. Nos. 5,938,321; 5,813,745;5,820,245; 5,673,994; 5,649,756; or 5,178,448, microphones, such asdisclosed in U.S. Pat. Nos. 6,243,003 and 6,278,377, speakers, acompass, such as disclosed in U.S. Pat. No. 5,924,212, a seat occupancydetector, a trip computer, an ONSTAR® system or the like (with all ofthe above-referenced patents commonly assigned to Donnelly Corporation,and with the disclosures of the referenced patents being herebyincorporated herein by reference in their entireties).

The reflective element assembly or assemblies of the present inventionmay include a printed circuit board (PCB), which may be attached to therear surface (e.g. the fourth surface) of the mirror element by, forexample, a suitable adhesive or the like. An example of such anarrangement is disclosed in commonly assigned U.S. Pat. No. 5,820,245,which is hereby incorporated herein by reference in its entirety. ThePCB optionally may include glare sensing and ambient photo sensors andelectrochromic circuitry that automatically dims the reflectivity of theelectrochromic mirror element when glare conditions are detected, suchas at nighttime or the like. Alternately, the PCB may be snap connected,by a clip or otherwise attached, to a plastic plate that itself isadhered to the electrochromic element.

The printed circuit board may include electronic or electrical circuitryfor actuating the variable reflectance of the reflective element and foroperating other electrical or electronic functions supported in therearview mirror assembly. The circuit board may support, for example,light emitting diodes (LEDs) for illuminating indicia on displayelements provided on the chin of the bezel of the mirror assembly ordisplay devices provided on/the reflective element, or map or dash boardlights or the like. The circuit board may be independently supportedfrom the reflective element or in the casing or may be mounted to thereflective element's rear or fourth surface on a separate plate or maybe directly adhered to the rear surface by a suitable adhesive.Reference is made to U.S. Pat. Nos. 5,671,996 and 5,820,245, thedisclosures of which are hereby incorporated herein by reference intheir entireties.

Therefore, the present invention provides an electro-optic orelectrochromic reflective element assembly which requires a minimalbezel or no bezel around the perimeter edges of the reflective elementassembly. The reflective element assembly may provide for electricalconnection to the conductive layer at the front substrate that issubstantially non viewable through the front substrate. The presentinvention may also provide a reflective element assembly which mayprovide a flush alignment of the edges of the substrates along at leastone side or edge, while providing a relief area for electricalconnection to one of the substrates along the flush or aligned edges.The reflective element assembly of the present invention providesenhanced manufacturing of the reflective element assembly, since theflush alignment of the substrates obviates the need for stepped spacersor pins positioned along the upper or lower edges of the substratesduring assembly of the reflective element assembly.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the presentinvention, which is intended to be limited only by the scope of theappended claims, as interpreted according to the principles of patentlaw.

1. A rearview mirror assembly for a vehicle, said rearview mirrorassembly comprising: an electro-optic reflective element, saidreflective element providing a rearward field of view to a driver of avehicle when a vehicle is equipped with said rearview mirror assembly;said electro-optic reflective element comprising an electro-optic mediumdisposed between a first substrate and a second substrate; said firstsubstrate being closer to the driver of the vehicle than said secondsubstrate when the vehicle is equipped with said rearview mirrorassembly; said first substrate having a first surface and a secondsurface; said first surface being closer to the driver of the vehiclethan said second surface when the vehicle is equipped with said rearviewmirror assembly; said second substrate having a third surface and afourth surface; said third surface being closer to the driver of thevehicle than said fourth surface when the vehicle is equipped with saidrearview mirror assembly; an overhang region at an edge region of saidfirst substrate that extends beyond a corresponding edge region of saidsecond substrate; a transparent electrical conductor disposed at saidsecond surface of said first substrate; an electrically conductivemirror reflector disposed at said third surface of said secondsubstrate; said mirror reflector including a tab portion that at leastpartially encompasses an edge dimension of said second substrate; saidsecond substrate having a non-conductive perimeter region at said thirdsurface and devoid of said mirror reflector except at said tab portion;a non-conductive seal disposed between said first and second substratesand encompassing at least a portion of said mirror reflector and atleast a portion of said non-conductive perimeter region; at least onehiding layer disposed around a perimeter region of said second surfaceof said first substrate; said at least one hiding layer beingsubstantially non-transparent so as to render the presence of saidnon-conductive seal substantially not noticeable to a viewer directlyviewing said rearview mirror assembly when the vehicle is normallyequipped with said rearview mirror assembly; a first electricalconnector in electrical connection with said transparent electricalconductor, said first electrical connector connecting to saidtransparent electrical conductor via said overhang region; and a secondelectrical connector in electrical connection with said tab portion ofsaid mirror reflector.
 2. The rearview mirror assembly of claim 1,wherein said second electrical connector electrically connects to saidtab portion of said mirror reflector via said fourth surface of saidsecond substrate.
 3. The rearview mirror assembly of claim 2, whereinsaid first electrical connector electrically connects to saidtransparent electrical conductor via said fourth surface of said secondsubstrate.
 4. The rearview mirror assembly of claim 1, wherein saidfirst electrical connector electrically connects to said transparentelectrical conductor via said fourth surface of said second substrate.5. The rearview mirror assembly of claim 1, wherein said at least onehiding layer renders the presence of said first electrical connectorsubstantially not noticeable to a viewer directly viewing said rearviewmirror assembly when the vehicle is normally equipped with said rearviewmirror assembly.
 6. The rearview mirror assembly of claim 1, whereinsaid tab portion of said mirror reflector extends substantially acrosssaid edge dimension of said second substrate.
 7. The rearview mirrorassembly of claim 6, wherein said second electrical connectorelectrically connects to said tab portion of said mirror reflector viasaid fourth surface of said second substrate.
 8. The rearview mirrorassembly of claim 1, wherein said mirror reflector comprises a metalliclayer.
 9. The rearview mirror assembly of claim 8, wherein said metalliclayer comprises at least one of (i) silver, (ii) aluminum, (iii) analloy of silver, and (iv) an alloy of aluminum.
 10. The rearview mirrorassembly of claim 1, wherein said mirror reflector includes atransparent electrical conductor.
 11. The rearview mirror assembly ofclaim 1 further comprising another overhang region at another edgeregion of said first substrate that extends beyond a corresponding otheredge region of said second substrate.
 12. The rearview mirror assemblyof claim 11, wherein said other edge region of said first substrate isgenerally opposite said edge region of said first substrate.
 13. Therearview mirror assembly of claim 11, wherein said second electricalconnector connects to said tab portion of said mirror reflector behindsaid other overhang region.
 14. The rearview mirror assembly of claim 1,wherein said first electrical connector comprises at least one pin thatextends from a portion of said reflective element generally at saidfourth surface, said at least one pin extending toward said secondsurface of said first substrate to electrically connect to saidtransparent electrical conductor.
 15. The rearview mirror assembly ofclaim 1 including a conductive material disposed at said overhang regionof said first substrate, said first electrical connector being inelectrical connection with said transparent electrical conductor viasaid conductive material.
 16. The rearview mirror assembly of claim 1,wherein said overhang region is at one of an upper edge region and alower edge region of said first substrate and relative to the groundwhen the vehicle is equipped with said rearview mirror assembly.
 17. Therearview mirror assembly of claim 1, wherein said at least one hidinglayer comprises at least one of a metal layer, a metal compound layer, achromium metal layer, a chrome oxide layer, a nickel oxide layer, asilver oxide layer, a frit layer and a conductive epoxy layer.
 18. Therearview mirror assembly of claim 1, wherein said at least one hidinglayer comprises a conductive hiding layer that is in electricalconnection with said transparent electrical conductor, said firstelectrical connector being electrically connected to said transparentelectrical conductor via said conductive hiding layer.
 19. The rearviewmirror assembly of claim 1, wherein said transparent electricalconductor is disposed rearward of said at least one hiding layer andbetween said at least one hiding layer and said first electricalconnector.
 20. The rearview mirror assembly of claim 1, wherein said atleast one hiding layer comprises a metal layer.
 21. The rearview mirrorassembly of claim 1, wherein said at least one hiding layer comprises ametal compound layer.
 22. The rearview mirror assembly of claim 1,wherein said at least one hiding layer comprises a chromium metal layer.23. The rearview mirror assembly of claim 1, wherein said non-conductiveperimeter region is at least partially along and proximate to said edgeregion of said second substrate generally at said overhang region. 24.The rearview mirror assembly of claim 1, wherein said rearview mirrorassembly comprises an interior rearview mirror assembly adapted formounting to an interior portion of the vehicle.
 25. The rearview mirrorassembly of claim 1, wherein said rearview mirror assembly comprises anexterior rearview mirror assembly adapted for mounting to an exteriorportion of the vehicle.
 26. The rearview mirror assembly of claim 1,wherein said electro-optic reflective element comprises anelectrochromic reflective element comprising an electrochromic mediumdisposed between said first substrate and said second substrate.
 27. Arearview mirror assembly for a vehicle, said rearview mirror assemblycomprising: an electro-optic reflective element, said reflective elementproviding a rearward field of view to a driver of a vehicle when avehicle is equipped with said rearview mirror assembly; saidelectro-optic reflective element comprising an electro-optic mediumdisposed between a first substrate and a second substrate; said firstsubstrate being closer to the driver of the vehicle than said secondsubstrate when the vehicle is equipped with said rearview mirrorassembly; said first substrate having a first surface and a secondsurface; said first surface being closer to the driver of the vehiclethan said second surface when the vehicle is equipped with said rearviewmirror assembly; said second substrate having a third surface and afourth surface; said third surface being closer to the driver of thevehicle than said fourth surface when the vehicle is equipped with saidrearview mirror assembly; an overhang region at an edge region of saidfirst substrate that extends beyond a corresponding edge region of saidsecond substrate; a transparent electrical conductor disposed at saidsecond surface of said first substrate; an electrically conductivemirror reflector disposed at said third surface of said secondsubstrate; said mirror reflector including a tab portion that at leastpartially encompasses an edge dimension of said second substrate andthat extends substantially across said edge dimension of said secondsubstrate; said second substrate including a non-conductive perimeterregion at said third surface and devoid of said mirror reflector exceptat said tab portion; a non-conductive seal disposed between said firstand second substrates and encompassing at least a portion of said mirrorreflector and at least a portion of said non-conductive perimeterregion; a first electrical connector in electrical connection with saidtransparent electrical conductor, said first electrical connectorconnecting to said transparent electrical conductor via said overhangregion; and a second electrical connector in electrical connection withsaid tab portion of said mirror reflector via said fourth surface ofsaid second substrate.
 28. The rearview mirror assembly of claim 27further comprising at least one hiding layer disposed around a perimeterregion of said second surface of said first substrate, said at least onehiding layer being substantially non-transparent so as to render thepresence of said non-conductive seal substantially not noticeable to aviewer directly viewing said rearview mirror assembly when the vehicleis normally equipped with said rearview mirror assembly.
 29. Therearview mirror assembly of claim 28, wherein said at least one hidinglayer comprises a conductive hiding layer that is in electricalconnection with said transparent electrical conductor, said firstelectrical connector being electrically connected to said transparentelectrical conductor via said conductive hiding layer.
 30. The rearviewmirror assembly of claim 28, wherein said transparent electricalconductor is disposed rearward of said at least one hiding layer andbetween said at least one hiding layer and said first electricalconnector.
 31. The rearview mirror assembly of claim 28, wherein said atleast one hiding layer comprises at least one of a metal layer, a metalcompound layer, a chromium metal layer, a chrome oxide layer, a nickeloxide layer, a silver oxide layer, a frit layer and a conductive epoxylayer.
 32. The rearview mirror assembly of claim 28, wherein said atleast one hiding layer renders the presence of said first electricalconnector substantially not noticeable to a viewer directly viewing saidrearview mirror assembly when the vehicle is normally equipped with saidrearview mirror assembly.
 33. The rearview mirror assembly of claim 27,wherein said first electrical connector electrically connects to saidtransparent electrical conductor via said fourth surface of said secondsubstrate.
 34. The rearview mirror assembly of claim 27, wherein saidmirror reflector comprises a metallic layer.
 35. The rearview mirrorassembly of claim 34, wherein said metallic layer comprises at least oneof (i) silver, (ii) aluminum, (iii) an alloy of silver, and (iv) analloy of aluminum.
 36. The rearview mirror assembly of claim 27including a conductive material disposed at said overhang region of saidfirst substrate, said first electrical connector being in electricalconnection with said transparent electrical conductor via saidconductive material.
 37. The rearview mirror assembly of claim 27,wherein said non-conductive perimeter region is at least partially alongand proximate to said edge region of said second substrate generally atsaid overhang region.
 38. The rearview mirror assembly of claim 27,wherein said rearview mirror assembly comprises an interior rearviewmirror assembly adapted for mounting to an interior portion of thevehicle.
 39. The rearview mirror assembly of claim 27, wherein saidrearview mirror assembly comprises an exterior rearview mirror assemblyadapted for mounting to an exterior portion of the vehicle.
 40. Therearview mirror assembly of claim 27, wherein said electro-opticreflective element comprises an electrochromic reflective elementcomprising an electrochromic medium disposed between said firstsubstrate and said second substrate.
 41. A rearview mirror assembly fora vehicle, said rearview mirror assembly comprising: an electrochromicreflective element, said reflective element providing a rearward fieldof view to a driver of a vehicle when a vehicle is equipped with saidrearview mirror assembly; said electrochromic reflective elementcomprising an electrochromic medium disposed between a first substrateand a second substrate; said first substrate being closer to the driverof the vehicle than said second substrate when the vehicle is equippedwith said rearview mirror assembly; said first substrate having a firstsurface and a second surface; said first surface being closer to thedriver of the vehicle than said second surface when the vehicle isequipped with said rearview mirror assembly; said second substratehaving a third surface and a fourth surface; said third surface beingcloser to the driver of the vehicle than said fourth surface when thevehicle is equipped with said rearview mirror assembly; an overhangregion at an edge region of said first substrate that extends beyond acorresponding edge region of said second substrate; a transparentelectrical conductor disposed at said second surface of said firstsubstrate; an electrically conductive mirror reflector disposed at saidthird surface of said second substrate; said mirror reflector includinga tab portion that at least partially encompasses an edge dimension ofsaid second substrate; said second substrate having a non-conductiveperimeter region at said third surface and devoid of said mirrorreflector except at said tab portion; a non-conductive seal disposedbetween said first and second substrates and encompassing at least aportion of said mirror reflector and at least a portion of saidnon-conductive perimeter region; a metallic hiding layer disposed arounda perimeter region of said second surface of said first substrate; saidmetallic hiding layer being substantially non-transparent so as torender the presence of said non-conductive seal substantially notnoticeable to a viewer directly viewing said rearview mirror assemblywhen the vehicle is normally equipped with said rearview mirrorassembly; a first electrical connector in electrical connection withsaid transparent electrical conductor, said first electrical connectorconnecting to said transparent electrical conductor via said overhangregion; and a second electrical connector in electrical connection withsaid tab portion of said mirror reflector.
 42. The rearview mirrorassembly of claim 41, wherein said tab portion of said mirror reflectorextends substantially across said edge dimension of said secondsubstrate.
 43. The rearview mirror assembly of claim 42, wherein saidsecond electrical connector electrically connects to said tab portion ofsaid mirror reflector via said fourth surface of said second substrate.44. The rearview mirror assembly of claim 41, wherein said metallichiding layer comprises a conductive metallic hiding layer that is inelectrical connection with said transparent electrical conductor, saidfirst electrical connector being electrically connected to saidtransparent electrical conductor via said conductive metallic hidinglayer.
 45. The rearview mirror assembly of claim 41, wherein saidtransparent electrical conductor is disposed rearward of said metallichiding layer and between said metallic hiding layer and said firstelectrical connector.
 46. The rearview mirror assembly of claim 41,wherein said rearview mirror assembly comprises an interior rearviewmirror assembly adapted for mounting to an interior portion of thevehicle.
 47. The rearview mirror assembly of claim 41, wherein saidrearview mirror assembly comprises an exterior rearview mirror assemblyadapted for mounting to an exterior portion of the vehicle.